<SUBMISSION>
<ACCESSION-NUMBER>0001193125-08-162724
<TYPE>S-8
<PUBLIC-DOCUMENT-COUNT>3
<FILING-DATE>20080731
<DATE-OF-FILING-DATE-CHANGE>20080731
<EFFECTIVENESS-DATE>20080731
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>CERUS CORP
<CIK>0001020214
<ASSIGNED-SIC>3841
<IRS-NUMBER>680262011
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>S-8
<ACT>33
<FILE-NUMBER>333-152680
<FILM-NUMBER>08982554
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>2411 STANWELL DR
<CITY>CONCORD
<STATE>CA
<ZIP>94520
<PHONE>9252886000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2525 STANWELL DRIVE
<STREET2>STE 300
<CITY>CONCORD
<STATE>CA
<ZIP>94520
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>CERUS TECHNOLOGIES INC
<DATE-CHANGED>19960731
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>S-8
<SEQUENCE>1
<FILENAME>ds8.htm
<DESCRIPTION>FORM S-8
<TEXT>
<HTML><HEAD>
<TITLE>Form S-8</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>As filed with the Securities and Exchange Commission on July 31, 2008 </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Registration No.&nbsp;333-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </B></FONT></P> <P
STYLE="font-size:3px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P
STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P STYLE="margin-top:4px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>UNITED STATES </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="3"><B>Washington, D.C. 20549 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>FORM S-8 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="3"><B>REGISTRATION STATEMENT </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>AND </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>POST-EFFECTIVE AMENDMENT NO. 1 TO </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>REGISTRATION STATEMENTS </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>NO. 333-145007, NO. 333-136452, NO. 333-127541, NO. 333-125043, NO. 333-109170, NO. 333-92254, NO. 333-63132, NO. 333-42588, NO. 333-84497, AND NO.
333-74991 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B><I>UNDER THE SECURITIES ACT OF 1933 </I></B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="6"><B>CERUS CORPORATION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Exact name of registrant as specified in its charter) </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Delaware</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>68-0262011</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(State or other jurisdiction of</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>incorporation or organization)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(I.R.S. Employer Identification No.)</B></FONT></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>2411 Stanwell Drive </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Concord, California 94520 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Address of Principal Executive Offices) (Zip Code)
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>2008&nbsp;Equity Incentive Plan </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>1999&nbsp;Equity Incentive Plan </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>1998&nbsp;Non-Officer Stock Option Plan </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Full title of the plans) </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Claes
Glassell </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>President and Chief Executive Officer </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>Cerus Corporation </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>2411 Stanwell Drive </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Concord, California 94520 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Name and address of agent for service)
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>(925) 288-6000 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>(Telephone number, including area code, of agent for service) </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B><I>Copies to: </I></B></FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Suzanne Sawochka Hooper, Esq. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Robert
L. Jones, Esq. </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Cooley Godward Kronish LLP </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>Five Palo Alto Square </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>3000 El Camino Real </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Palo Alto, California 94306-2155 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="2"><B>(650)&nbsp;843-5000 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated
filer, or a smaller reporting company. See the definitions of &#147;large accelerated filer,&#148; &#147;accelerated filer&#148; and &#147;smaller reporting company&#148; in Rule&nbsp;12b-2 of the Exchange Act. (Check one): </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Large accelerated filer&nbsp;<FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Accelerated filer&nbsp;<FONT FACE="WINGDINGS">&#254;</FONT></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Non-accelerated filer&nbsp;<FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Smaller reporting company&nbsp;<FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="5" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">(Do not check if a smaller reporting company)</FONT></TD></TR>
</TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>CALCULATION OF REGISTRATION FEE </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD WIDTH="44%"></TD>
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<TD WIDTH="13%"></TD>
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<TD WIDTH="13%"></TD></TR>
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<TD COLSPAN="9" VALIGN="bottom" STYLE="border-top:1px solid #000000">&nbsp;</TD></TR>
<TR>
<TD VALIGN="bottom" ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Title of securities</B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>to be registered</B></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="1"><B>Amount to be<BR>registered</B></FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Proposed</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>maximum</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>offering</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>price per</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>share</B></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Proposed</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>maximum</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>aggregate</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>offering</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>price</B></FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="1"><B>Amount of<BR>registration</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-left:1.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Common Stock, par value $0.001 per share</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-left:3.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Shares not previously registered</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">2,270,000(1)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">$5.13(2)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">$11,465,100 (2)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">$457.65(2)</FONT></TD></TR>
<TR>
<TD VALIGN="top" STYLE="BORDER-TOP:1px solid #000000"> <P STYLE="margin-left:3.00em; text-indent:-1.00em"><FONT FACE="Times New Roman" SIZE="2">Shares previously registered</FONT></P></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">6,265,185(1)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">N/A(3)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">N/A (3)</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-LEFT:1px solid #000000; BORDER-TOP:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="BORDER-TOP:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">N/A(3)</FONT></TD></TR>
<TR STYLE="font-size:1px">
<TD COLSPAN="9" VALIGN="bottom" STYLE="border-top:1px solid #000000">&nbsp;</TD></TR>
<TR STYLE="font-size:1px">
<TD COLSPAN="9" VALIGN="bottom" STYLE="border-top:1px solid #000000">&nbsp;</TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">This Registration Statement is (a)&nbsp;a new registration statement; (b)&nbsp;a Post-Effective Amendment
No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-74991), as filed with the Securities and Exchange Commission on March&nbsp;24, 1999 (the &#147;March 1999 Registration Statement&#148;); (c)&nbsp;a
Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-84497), as filed with the Securities and Exchange Commission on August&nbsp;4, 1999 (the &#147;August 1999 Registration
Statement&#148;); (d)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-42588), as filed with the Securities and Exchange Commission on July&nbsp;28, 2000 (the &#147;2000
Registration Statement&#148;); (e)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-63132), as filed with the Securities and Exchange Commission on June&nbsp;15, 2001 (the
&#147;2001 Registration Statement&#148;); (f)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-92254), as filed with the Securities and Exchange Commission on July&nbsp;11,
2002 (the &#147;2002 Registration Statement&#148;); (g)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-109170), as filed with the Securities and Exchange Commission on
September&nbsp;26, 2003 (the &#147;2003 Registration Statement&#148;); (h)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-125043), as filed with the Securities and Exchange
Commission on May&nbsp;19, 2005 (the &#147;May 2005 Registration Statement&#148;); (i)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-127541), as filed with the Securities
and Exchange Commission on August&nbsp;15, 2005 (the &#147;August 2005 Registration Statement&#148;); (j)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-136452), as filed
with the Securities and Exchange Commission on August&nbsp;9, 2006 (the &#147;2006 Registration Statement&#148;); and (k)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File
No.&nbsp;333-145007), as filed with the Securities and Exchange Commission on August&nbsp;1, 2007 (the &#147;2007 Registration Statement&#148;) ( the March 1999 Registration Statement, the August 1999 Registration Statement, the 2000 Registration
Statement, the 2001 Registration Statement, the 2002 Registration Statement, the 2003 Registration Statement, the May 2005 Registration Statement, the August 2005 Registration Statement, the 2006 Registration Statement, and the 2007 Registration
Statement are collectively referred herein as the &#147;Prior Registration Statements&#148;). Pursuant to the Prior Registration Statements, shares of common stock, par value $0.001, were registered for issuance under the Cerus Corporation 1998
Non-Officer Stock Option Plan and the Cerus Corporation 1999 Equity Incentive Plan, as amended (collectively, the &#147;Prior Plans&#148;). </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">This Registration Statement covers 2,270,000 shares, not previously registered, under the Cerus Corporation 2008 Equity Incentive Plan (the &#147;2008 Plan&#148;), which is the
successor plan to the Prior Plans. In addition, this Registration Statement covers up to 6,265,185 shares which were previously registered under the Prior Registration Statements for offer or sale under the Prior Plans and which may be offered or
sold under the 2008 Plan (the &#147;Carried Forward Shares&#148;). The Carried Forward Shares consist of shares remaining available for issuance under the Prior Plans and shares subject to currently outstanding options under the Prior Plans. In the
event any of the shares subject to outstanding options under the Prior Plans are not issued, such as when an option granted under any Prior Plan is canceled without being exercised, such shares will become available for issuance under the 2008 Plan.
Pursuant to Rule 416(a) of the Securities Act of 1933, as amended (the &#147;Securities Act&#148;), this Registration Statement shall also cover any additional shares of the Registrant&#146;s common stock that become issuable under the 2008 Plan and
the Prior Plans by reason of any stock dividend, stock split, recapitalization or other similar transaction effected without receipt of consideration that increases the number of outstanding shares of the Registrant&#146;s common stock.
</FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Estimated solely for the purpose of calculating the amount of the registration fee pursuant to Rule 457(h) of the Securities Act. The price per share and aggregate offering price
are based upon the average of the high and low prices of Registrant&#146;s Common Stock on July&nbsp;24, 2008 as reported on the Nasdaq Global Market. </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">The Carried Forward Shares were previously registered under the Prior Registration Statements; therefore, no filing fee with respect to those shares is required (Interpretation 89
under Section G of the Securities and Exchange Commission Division of Corporate Finance Manual of Publicly Available Telephone Interpretations (July&nbsp;1997) and Instruction E to the General Instructions to Form S-8). Each of the Post-Effective
Amendments to the Prior Registration Statements are filed here to reallocate the Carried Forward Shares from the Prior Registration Statements and to carry over the registration fees paid for the Carried Forward Shares from the Prior Registration
Statements. </FONT></TD></TR></TABLE> <P STYLE="font-size:4px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P
STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>STATEMENT PURSUANT TO GENERAL INSTRUCTION E TO FORM S-8 </B></FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation (the &#147;Company&#148;) has filed this Registration Statement to register under the Securities Act the offer and sale of 2,270,000
common shares, par value $0.001 per share, of beneficial interest, not previously registered, in the Company, and up to 6,265,185 common shares, par value $0.001 per share, of beneficial interest in the Company, which were previously registered (as
further described below) pursuant to the Cerus Corporation 1998 Non-Officer Stock Option Plan (the &#147;1998 Plan&#148;) and the Cerus Corporation 1999 Equity Incentive Plan (the &#147;1999 Plan&#148;). This registration statement is (a)&nbsp;a new
registration statement; (b)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-74991), as filed with the Securities and Exchange Commission on March&nbsp;24, 1999 (the
&#147;March 1999 Registration Statement&#148;); (c)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-84497), as filed with the Securities and Exchange Commission on
August&nbsp;4, 1999 (the &#147;August 1999 Registration Statement&#148;); (d)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-42588), as filed with the Securities and Exchange
Commission on July&nbsp;28, 2000 (the &#147;2000 Registration Statement&#148;); (e)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-63132), as filed with the Securities and
Exchange Commission on June&nbsp;15, 2001 (the &#147;2001 Registration Statement&#148;); (f)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-92254), as filed with the
Securities and Exchange Commission on July&nbsp;11, 2002 (the &#147;2002 Registration Statement&#148;); (g)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File No.&nbsp;333-109170), as filed
with the Securities and Exchange Commission on September&nbsp;26, 2003 (the &#147;2003 Registration Statement&#148;); (h)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form S-8 (File
No.&nbsp;333-125043), as filed with the Securities and Exchange Commission on May&nbsp;19, 2005 (the &#147;May 2005 Registration Statement&#148;); (i)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration statement on Form
S-8 (File No.&nbsp;333-127541), as filed with the Securities and Exchange Commission on August&nbsp;15, 2005 (the &#147;August 2005 Registration Statement&#148;); (j)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s registration
statement on Form S-8 (File No.&nbsp;333-136452), as filed with the Securities and Exchange Commission on August&nbsp;9, 2006 (the &#147;2006 Registration Statement&#148;); and (k)&nbsp;a Post-Effective Amendment No.&nbsp;1 to the registrant&#146;s
registration statement on Form S-8 (File No.&nbsp;333-145007), as filed with the Securities and Exchange Commission on August&nbsp;1, 2007 (the &#147;2007 Registration Statement&#148;) ( the March 1999 Registration Statement, the August 1999
Registration Statement, the 2000 Registration Statement, the 2001 Registration Statement, the 2002 Registration Statement, the 2003 Registration Statement, the May 2005 Registration Statement, the August 2005 Registration Statement, the 2006
Registration Statement, and the 2007 Registration Statement are collectively referred herein as the &#147;Prior Registration Statements&#148;). 6,265,185 shares of common stock, par value $0.001, registered hereby were registered for issuance under
the Cerus Corporation 1998 Non-Officer Stock Option Plan and the Cerus Corporation 1999 Equity Incentive Plan, as amended (collectively, the &#147;Prior Plans&#148;). </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">The 2008 Plan was approved and adopted at the Company&#146;s annual meeting of stockholders on June&nbsp;2, 2008 to supersede and replace the Prior Plans. The Company desires to have the common shares registered
hereunder and issuable pursuant to the 2008 Plan to include those common shares described above whose offer and sale were registered under the Prior Registration Statements. The shares carried over from the Prior Registration Statements are no
longer available for new awards under the Prior Plans. This Registration Statement covers 2,270,000 shares, not previously registered, under the 2008 Plan, which is the successor plan to the Prior Plans. In addition, this Registration Statement
covers up to 6,265,185 shares which were previously registered under the Prior Registration Statements for offer or sale under the Prior Plans and which may be offered or sold under the 2008 Plan (the &#147;Carried Forward Shares&#148;). The Carried
Forward Shares consist of shares remaining available for issuance under the Prior Plans and shares subject to currently outstanding options under the Prior Plans. In the event any of these shares subject to outstanding options are not issued under
the Prior Plans, such as when an option granted under any Prior Plan is canceled without being exercised, such shares will become available for issuance under the 2008 Plan. Pursuant to Rule 416(a) of the Securities Act, this Registration Statement
shall also cover any additional shares of the Company&#146;s Common Stock that become issuable under the 2008 Plan and the Prior Plans by reason of any stock dividend, stock split, recapitalization or other similar transaction effected without
receipt of consideration that increases the number of outstanding shares of the Company&#146;s Common Stock. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Consequently, in accordance
with the Interpretation 89 under Section&nbsp;G of the Securities and Exchange Commission Division of Corporate Finance Manual of Publicly Available Telephone Interpretations (July&nbsp;1997) and Instruction E to the General Instructions to Form
S-8: (a)&nbsp;the Company is (i)&nbsp;carrying over the Carried Forward Shares from the Prior Registration Statements, and (ii)&nbsp;registering the offer and sale of 2,270,000 new common shares, of which all 8,535,185 shares may be offered and sold
under the 2008 Plan pursuant to this Registration Statement; (b)&nbsp;the registration fee allocable to the Carried Forward Shares carried over from the Prior Registration Statements and paid in connection with the Prior Registration Statements is
carried over in this Registration Statement; and (c)&nbsp;the Prior Registration Statements are being amended on a post-effective basis to disclose the succession of the 2008 Plan to the Prior Plans, pursuant to this Registration Statement.
</FONT></P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE </B></FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The following documents filed by Cerus Corporation (the &#147;Company&#148;) with the Securities and Exchange Commission (&#147;SEC&#148;) are
incorporated by reference into this Registration Statement on Form S-8: </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(a)&nbsp;</B>The Company&#146;s Annual Report on Form 10-K for
the Company&#146;s fiscal year ended December&nbsp;31, 2007, filed with the SEC on February&nbsp;27, 2008. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(b)&nbsp;</B>The
Company&#146;s Quarterly Report on Form 10-Q for the quarter ended March&nbsp;31, 2008, filed with the SEC on May&nbsp;6, 2008. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2"><B></B><B>(c)&nbsp;</B>The Company&#146;s Quarterly Report on Form 10-Q for the quarter ended June&nbsp;30, 2008, filed with the SEC on July&nbsp;31, 2008.<B> </B></FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(d) </B>The Company&#146;s definitive proxy statement for the Company&#146;s stockholders&#146; meeting on June&nbsp;2, 2008 filed with the SEC on
April&nbsp;25, 2008. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(e)&nbsp;</B>The Company&#146;s Current Reports on Form 8-K filed with the SEC on February&nbsp;1,
2008,&nbsp;February&nbsp;21, 2008,&nbsp;March&nbsp;3, 2008, and May&nbsp;1, 2008. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B>(f)&nbsp;</B>The description of the Company&#146;s
Common Stock set forth in the Company&#146;s registration statement on Form 8-A, filed with the SEC on January&nbsp;8, 1997 including any amendments or reports filed for the purposes of updating this description. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">All other documents subsequently filed by the Company pursuant to Sections&nbsp;13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a
post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part of this Registration Statement
from the date of the filing of such documents. </FONT></P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>INDEMNIFICATION OF DIRECTORS AND OFFICERS </B></FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">As permitted by Delaware law, the Company&#146;s amended and restated certificate of incorporation provides that no director will be personally liable to
the Company or the Company&#146;s stockholders for monetary damages for breach of fiduciary duty as a director, except for liability: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">for any breach of the duty of loyalty to the Company or the Company&#146;s stockholders; </FONT></P></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">for acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law; </FONT></P></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">for unlawful payment of dividends or unlawful stock repurchases or redemptions under Section&nbsp;174 of the Delaware General Corporation Law; and
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">for any transaction from which the director derived an improper personal benefit. </FONT></P></TD></TR></TABLE> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The Company&#146;s amended and restated certificate of incorporation further provides that the Company must indemnify the Company&#146;s directors to the
fullest extent permitted by Delaware law. In addition, the Company&#146;s amended and restated bylaws provide that: </FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the Company is required to indemnify the Company&#146;s directors and officers to the fullest extent not prohibited by Delaware law, subject to limited exceptions;
</FONT></P></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the Company may indemnify the Company&#146;s other employees and agents as set forth in the Delaware General Corporation Law; </FONT></P></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the Company is required to advance expenses to the Company&#146;s directors and executive officers as incurred in connection with legal proceedings against them for
which they may be indemnified, against an undertaking by the indemnified party to repay such advances if it is ultimately determined that the indemnified party is not entitled to indemnification; and </FONT></P></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="3%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">&#149;</FONT></TD>
<TD WIDTH="1%" VALIGN="top"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD ALIGN="left" VALIGN="top"> <P ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">the rights conferred in the amended and restated bylaws are not exclusive. </FONT></P></TD></TR></TABLE> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">The Company has entered into indemnification agreements with each of the Company&#146;s directors and executive officers that require the Company to
indemnify these people against expenses, witness fees, damages, judgments, fines and settlement amounts incurred by the director or officer in any action or proceeding, whether actual, pending or threatened, subject to certain limitations, to which
any of these people may be made a party by reason of the fact that he or she is or was a director or an executive officer of the Company or is or was serving or at any time serves at the request of the Company as a director, officer, employee or
other agent of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise. </FONT></P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBITS </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="4%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="border-bottom:1px solid #000000;width:28pt" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Exhibit<BR>Number</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="1"><B>Description</B></FONT></P></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Restated Certificate of Incorporation of Cerus Corporation, as amended to date(1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Amended and Restated Bylaws of Cerus(2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Specimen Stock Certificate(3)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Opinion of Cooley Godward Kronish LLP</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Consent of Independent Registered Public Accounting Firm</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Consent of Cooley Godward Kronish LLP- Contained in Opinion of Cooley Godward Kronish LLP filed as Exhibit&nbsp;5.1 to this Registration Statement</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">24&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Power of Attorney- Contained on the signature pages</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 1998 Non-Officer Stock Option Plan(5)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 1999 Equity Incentive Plan(4)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.3&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 2008 Equity Incentive Plan(6)</FONT></TD></TR>
</TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Current Report on Form 8-K (File No. 0-12937), dated November&nbsp;3, 1999. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Current Report on Form 8-K (File No. 0-12937), dated June&nbsp;19, 2008. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Registration Statement on Form S-1 (File No.&nbsp;333-11341) and amendments thereto. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Quarterly Report on Form 10-Q for the quarter ended June 30, 2007. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(5)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to Cerus&#146; Registration Statement on Form S-8 filed with the SEC on March&nbsp;24, 1999. (No.&nbsp;333-74991). </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(6)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to Cerus&#146; Current Report on Form 8-K filed with the SEC on June&nbsp;6, 2008 </FONT></TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>UNDERTAKINGS </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>1</B>.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">The undersigned registrant hereby undertakes: </FONT></TD></TR></TABLE> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(<B>a</B>)
To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement: </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman"
SIZE="2">(<B>i</B>) To include any prospectus required by Section&nbsp;10(a)(3) of the Securities Act; </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(<B>ii</B>) To
reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the
information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any
deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) of the Securities Act if, in the aggregate, the changes in volume and price
represent no more than a 20% change in the maximum aggregate offering price set forth in the &#147;Calculation of Registration Fee&#148; table in the effective registration statement. </FONT></P> <P
STYLE="margin-top:6px;margin-bottom:0px; margin-left:4%; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(<B>iii</B>) To include any material information with respect to the plan of distribution not previously disclosed in the registration
statement or any material change to such information in the registration statement; </FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px; margin-left:8%"><FONT FACE="Times New Roman" SIZE="2"><I>provided, however</I>, that paragraphs (a)(i) and
(a)(ii) of this section do not apply if the registration statement is on Form S-8, and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the
registrant pursuant to Section&nbsp;13 or Section&nbsp;15(d) of the Securities Exchange Act of 1934 (the &#147;Exchange Act&#148;) that are incorporated by reference in the registration statement. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">(<B>b</B>) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2"><B></B>(<B>c</B>) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the
termination of the offering.<B> </B></FONT></P> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>2</B>.</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">The undersigned registrant hereby undertakes to deliver or cause to be delivered with the prospectus, to each person to whom the prospectus is sent or given, the latest annual
report to security holders that is incorporated by reference in the prospectus and furnished pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the Exchange Act; and, where interim financial information required to be
presented by Article 3 of Regulation S-X are not set forth in the prospectus, to deliver, or cause to be delivered to each person to whom the prospectus is sent or given, the latest quarterly report that is specifically incorporated by reference in
the prospectus to provide such interim financial information. </FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>3.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B></B>Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the
foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In
the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit
or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to
a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue. </FONT></TD></TR></TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>SIGNATURES </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2">Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly
caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Concord, State of California, on July&nbsp;30, 2008. </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><DIV ALIGN="right">
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="40%" BORDER="0">

<TR>
<TD WIDTH="6%"></TD>
<TD VALIGN="bottom" WIDTH="2%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2"><B>CERUS CORPORATION</B></FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Claes Glassell</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Claes Glassell</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><I></I><I>President and Chief Executive Officer</I></FONT></TD></TR>
</TABLE></DIV>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>POWER OF ATTORNEY </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT
FACE="Times New Roman" SIZE="2"><B>KNOW ALL PERSONS BY THESE PRESENTS</B>, that each person whose signature appears below constitutes and appoints Claes Glassell and William J. Dawson, and each or any of them, his or her true and lawful
attorney-in-fact and agent, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement,
and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform
each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of
them, or their or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">Pursuant to the requirements of the
Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated. </FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="35%"></TD>
<TD VALIGN="bottom" WIDTH="14%"></TD>
<TD WIDTH="32%"></TD>
<TD VALIGN="bottom" WIDTH="14%"></TD>
<TD></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="1"><B>Signature</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Title</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="1"><B>Date</B></FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Claes Glassell</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Claes
Glassell</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">President and Chief Executive Officer</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><I>(Principal Executive and Financial Officer)</I></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July&nbsp;30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ William J. Dawson</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">William J. Dawson</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Vice President, Finance and</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2">Chief Financial Officer</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><I>(Principal Accounting Officer)</I></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ B.J. Cassin</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">B. J.
Cassin</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Timothy B. Anderson</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Timothy B. Anderson</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Lawrence M. Corash</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Laurence M. Corash, M.D.</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Bruce C. Cozadd</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">Bruce C. Cozadd</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ William R. Rohn</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman"
SIZE="2">William R. Rohn</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"> <P STYLE="margin-top:0px;margin-bottom:0px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Gail Schulze</FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="2">Gail
Schulze</FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">Director</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">July 30, 2008</FONT></TD></TR>
</TABLE>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBIT INDEX </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="4%"></TD>
<TD WIDTH="92%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="border-bottom:1px solid #000000;width:28pt" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>Exhibit<BR>Number</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="1"><B>Description</B></FONT></P></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Restated Certificate of Incorporation of Cerus Corporation, as amended to date(1)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.2</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Amended and Restated Bylaws of Cerus(2)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4.3</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Specimen Stock Certificate(3)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">5.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Opinion of Cooley Godward Kronish LLP</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Consent of Independent Registered Public Accounting Firm</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">23.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Consent of Cooley Godward Kronish LLP- Contained in Opinion of Cooley Godward Kronish LLP filed as Exhibit&nbsp;5.1 to this Registration Statement</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">24&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Power of Attorney- Contained on the signature pages</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.1&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 1998 Non-Officer Stock Option Plan(5)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.2&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 1999 Equity Incentive Plan(4)</FONT></TD></TR>
<TR>
<TD HEIGHT="8"></TD>
<TD HEIGHT="8" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">99.3&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation 2008 Equity Incentive Plan(6)</FONT></TD></TR>
</TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(1)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Current Report on Form 8-K (File No. 0-12937), dated November&nbsp;3, 1999. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(2)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Current Report on Form 8-K (File No. 0-12937), dated June&nbsp;19, 2008. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(3)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Registration Statement on Form S-1 (File No.&nbsp;333-11341) and amendments thereto. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(4)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Incorporated by reference to Cerus&#146; Quarterly Report on Form 10-Q for the quarter ended June 30, 2007. </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(5)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to Cerus&#146; Registration Statement on Form S-8 filed with the SEC on March&nbsp;24, 1999. (No.&nbsp;333-74991). </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(6)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Filed as an exhibit to Cerus&#146; Current Report on Form 8-K filed with the SEC on June&nbsp;6, 2008 </FONT></TD></TR></TABLE>
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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>2
<FILENAME>dex51.htm
<DESCRIPTION>OPINION OF COOLEY GODWARD KRONISH LLP
<TEXT>
<HTML><HEAD>
<TITLE>Opinion of Cooley Godward Kronish LLP</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Exhibit&nbsp;5.1 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2">July&nbsp;31, 2008 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Cerus Corporation </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">2525 Stanwell
Drive, Suite 300 </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Concord, CA 94520 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Ladies and Gentlemen:
</FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">You have requested our opinion with respect to certain matters in connection with the filing by Cerus Corporation (the &#147;Company&#148;) of a
Registration Statement on Form S-8 (the &#147;Registration Statement&#148;) with the Securities and Exchange Commission covering the offering of up to 2,270,000 shares of the Company&#146;s Common Stock, $0.001 par value (the &#147;Shares&#148;),
pursuant to its 2008 Equity Incentive Plan (the &#147;2008 Plan&#148;), and up to 6,265,185 shares of the Company&#146;s Common Stock, $0.001 par value (the &#147;Additional Shares&#148;), which were previously registered in connection with the
Company&#146;s 1999 Equity Incentive Plan and the Company&#146;s 1998 Non-Officer Stock Option Plan (collectively, the &#147;Prior Plans&#148;), and which may be offered or sold under the 2008 Plan, which is the successor plan to the Prior Plans.
</FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">In connection with this opinion, we have examined the Registration Statement and related Prospectus, the Company&#146;s Certificate of Incorporation and
By-laws, as amended, and such other documents, records, certificates, memoranda and other instruments as we deem necessary as a basis for this opinion. We have assumed the genuineness and authenticity of all documents submitted to us as originals,
the conformity to originals of all documents submitted to us as copies thereof, and the due execution and delivery of all documents where due execution and delivery are a prerequisite to the effectiveness thereof. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares and the Additional Shares, when sold and issued in accordance with the 2008
Plan, the Registration Statement and related Prospectus, will be validly issued, fully paid, and nonassessable (except as to shares issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such
deferred payments are made in full). </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">We consent to the filing of this opinion as an exhibit 5.1 to the Registration Statement. </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
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<TD WIDTH="7%"></TD>
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<TD WIDTH="92%"></TD></TR>
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<TD VALIGN="top" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2">Very truly yours,</FONT></TD></TR>
<TR>
<TD HEIGHT="8" COLSPAN="3"></TD></TR>
<TR>
<TD VALIGN="top" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2">Cooley Godward Kronish <SMALL>LLP</SMALL></FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Suzanne Sawochka Hooper</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Suzanne Sawochka Hooper</FONT></TD></TR>
</TABLE>
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</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>3
<FILENAME>dex231.htm
<DESCRIPTION>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
<TEXT>
<HTML><HEAD>
<TITLE>Consent of Independent Registered Public Accounting Firm</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2">Exhibit&nbsp;23.1 </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">We consent to the incorporation by reference in the
Registration Statement (Form S-8) pertaining to the 2008 Equity Incentive Plan, 1998 Non-Officer Stock Option Plan, and 1999 Equity Incentive Plan, as amended, of Cerus Corporation of our reports dated February&nbsp;26, 2008, with respect to the
consolidated financial statements of Cerus Corporation included in its Annual Report (Form 10-K) for the year ended December&nbsp;31, 2007, and the effectiveness of internal control over financial reporting of Cerus Corporation filed with the
Securities and Exchange Commission. </FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px; margin-left:56%" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">/s/ Ernst&nbsp;&amp; Young LLP </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">San Jose, California </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">July&nbsp;28, 2008 </FONT></P>
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