Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2015

Property and equipment consist of the following (in thousands):


	As of		As of
	December 31, 2015		December 31, 2014
Lab equipment and machinery	$	55,649	$	53,412
Leasehold improvements		6,116		5,892
Computer equipment and software		4,263		3,774
Furniture and fixtures		207		197
Construction in progress		1,625		847
Total property and equipment		67,860		64,122
Less accumulated depreciation		(52,125)		(45,016)
Property and equipment, net	$	15,735	$	19,106

Schedule of depreciation expense

The following table presents depreciation expense included in the Consolidated Statement of Operations and includes amortization of leasehold improvements (in thousands):


	Years Ended December 31,
	2015		2014		2013
Depreciation expense	$	7,314	$	10,220	$	8,781