Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities
Net loss	$ (29,838)	$ (22,202)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	2,188	1,020
Stock-based compensation expense	4,713	3,393
Non-cash interest expense	68	133
Loss on disposal of fixed assets	24
Change in fair value of preferred stock warrants		1
Changes in operating assets and liabilities:
Accounts receivable	(4,474)	1,160
Prepaid expenses and other assets	(104)	(753)
Inventory	(3,943)	(976)
Other non-current assets	(21)	(33)
Accounts payable	(835)	152
Accrued compensation and benefits, other accrued expenses and other current liabilities	573	(55)
Contract acquisition costs	533
Other non-current liabilities	10,068
Deferred revenue	(604)	(2,453)
Net cash used in operating activities	(21,652)	(20,613)
Investing activities
Purchases of property and equipment	(10,303)	(1,397)
Purchase of investments		(150)
Acquisitions, net of cash acquired	(14,529)	(3,800)
Net cash used in investing activities	(24,832)	(5,347)
Financing activities
Net proceeds		(53)
Proceeds from stock options exercised	2,176	684
Proceeds from ESPP purchase	799
Payments on notes payable	(50)	(1,930)
Net cash provided by (used in) financing activities	115,473	(1,299)
Net increase (decrease) in cash and cash equivalents	68,989	(27,259)
Effect of foreign currency exchange rate on cash	(65)
Cash, restricted cash, and cash equivalents at beginning of period	45,429	79,682
Cash, restricted cash, and cash equivalents at end of period	114,353	52,423
Supplemental cash flow information
Cash paid for interest	478	506
Purchases of property and equipment included in accounts payable	45
191,152 shares of common stock issued in connection with the acquisition of Uman	5,467
Purchases of property and equipment included in other non-current liabilities	7,750
Reconciliation of cash, cash equivalents, and restricted cash:
Total cash, cash equivalents, and restricted cash	45,429	$ 79,682
At-the-market offering
Financing activities
Net proceeds	48,019
Underwritten public offering
Financing activities
Net proceeds	$ 64,529