Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of property and equipment
Property and equipment, Gross	$ 4,495	$ 4,329
Less accumulated depreciation	(2,952)	(2,726)
Property and equipment, net	1,543	1,603
Laboratory equipment [Member]
Summary of property and equipment
Property and equipment, Gross	2,950	2,851
Furniture and Fixtures [Member]
Summary of property and equipment
Property and equipment, Gross	499	442
Leasehold Improvements [Member]
Summary of property and equipment
Property and equipment, Gross	$ 1,046	$ 1,036

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

+ References+ Details

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details

- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References+ Details