v3.20.2
Balance Sheet Account Details
 9 Months Ended
Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Balance Sheet Account Details Balance Sheet Account Details
September 30,
2020		December 31,
2019
Accounts receivable, net:
Accounts receivable, trade1
$5,749,000 $6,889,000 
Less allowance for doubtful accounts(1,889,000)(555,000)
$3,860,000 $6,334,000 
1Includes $635,000 of accounts receivable from diagnostic services.

The Company extends credit to its customers in the normal course of business based upon an evaluation of each customer’s credit history, financial condition, and other factors. Estimates of allowances for doubtful accounts are determined by evaluating individual customer circumstances, historical payment patterns, length of time past due, and economic and other factors. During the nine months ended September 30, 2020, the Company recorded bad debt expense of $1,334,000, which is included in selling, general and administrative expenses.

 September 30,
2020		December 31,
2019
Inventory:
Materials and supplies$2,622,000 $951,000 
Finished goods1,971,000 2,493,000 
$4,593,000 $3,444,000