Inventories are stated at the lower of cost or net realizable value on a first-in, first-out basis and are comprised of the following (in thousands):

	June 30, 2019		December 31, 2018
Raw materials	$	1,241	$	639
Work-in-process		1,300		1,713
Finished goods		559		325
Total inventories, net	$	3,100	$	2,677

	June 30, 2019			December 31, 2018
Office and computer equipment	$	409		$	409
Software		762			751
Laboratory equipment		4,747			4,636
Furniture		194			200
Manufacturing equipment		695			695
Manufacturing tooling and molds		255			255
T2-owned instruments and components		7,483			6,796
Leasehold improvements		3,461			3,437
Construction in progress		1,589			1,443
		19,595			18,622
Less accumulated depreciation and amortization		(12,333	)		(11,307	)
Property and equipment, net	$	7,262		$	7,315

Construction in progress is primarily comprised of equipment that have not been placed in service. T2-owned instruments and components is comprised of raw materials and work-in-process inventory that are expected to be used or used to produce T2-owned instruments, based on our business model and forecast, and completed instruments that will be used for internal research and development, clinical studies or reagent rental agreements with customers. At June 30, 2019, there were $1.0 million of raw materials and work-in-process inventory in T2-owned instruments and components compared to $0.3 million at December 31, 2018. Completed T2-owned instruments are placed in service once installation procedures are completed and are depreciated over five years. Depreciation expense for T2-owned instruments placed at customer sites pursuant to reagent rental agreements is recorded as a component of cost of product revenue and totaled approximately $0.2 million for the three months ended June 30, 2019 and 2018 and $0.4 million and $0.5 million for the six months ended June 30, 2019 and 2018, respectively. Depreciation expense for T2-owned instruments used for internal research and development and clinical studies is recorded as a component of research and development expense. Depreciation and amortization expense of $0.6 million was charged to operations for the three months ended June 30, 2019 and 2018 and $1.2 million for the six months ended June 30, 2019 and 2018. Included within property and equipment, net, are assets under finance leases. Total property and equipment, gross, included $3.6 million for property and equipment recorded under finance leases as of June 30, 2019 and December 31, 2018. Accumulated depreciation and amortization included $2.8 million and $2.6 million for property and equipment recorded under finance leases as of June 30, 2019 and December 31, 2018, respectively.

	June 30, 2019		December 31, 2018
Accrued payroll and compensation	$	2,773	$	2,940
Accrued research and development expenses		281		359
Accrued professional services		517		576
Operating lease liabilities		1,844		—
Other accrued expenses		3,408		2,198
Total accrued expenses and other current liabilities	$	8,823	$	6,073

At June 30, 2019 and December 31, 2018, the Company classified $1.9 million and $1.4 million, respectively, related to a fee associated with the Company’s Term Loan Agreement (Note 6), as other accrued expenses in the table above to match the current classification of the associated debt.