Condensed Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities
Net loss	$ (20,366,469)	$ (15,698,139)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,086,752	473,799
Accretion of discount on NuvoGen obligation	156,103	229,232
Bad debt expense, net of recoveries		44,854
Provision for excess inventory	437,893	273,752
Amortization of Growth Term Loan discount and issuance costs	415,355	274,486
Loss on settlement of convertible notes		705,217
Amortization of discount on convertible notes		90,222
Stock-based compensation expense	552,054	223,787
Change in redeemable convertible preferred stock warrant liability	0	239,683
Accretion of incentive from landlord	(94,667)
Accrued interest on available-for-sale securities investments	130,576
Loss on disposal of assets		67,780
Changes in operating assets and liabilities:
Accounts receivable	124,385	59,444
Inventory	(104,277)	(854,120)
Prepaid expenses and other	3,911	(505,918)
Accounts payable	367,529	(254,423)
Accrued liabilities	(258,073)	(47,367)
Deferred revenue	236,187	(8,532)
Net cash used in operating activities	(17,312,741)	(14,686,243)
Investing activities
Purchase of property and equipment	(1,859,155)	(950,278)
Sales, redemptions and maturities of available-for-sale securities	23,000,000
Purchase of available-for-sale securities	(3,381,271)	(36,473,957)
Net cash provided by (used in) investing activities	17,759,574	(37,424,235)
Financing activities
Proceeds from initial public offering		47,654,190
Deferred offering costs		(1,002,930)
Proceeds from Growth Term Loan	5,000,000
Payments on Growth Term Loan	(2,932,482)
Proceeds from convertible notes		4,500,000
Deferred convertible note financing costs		(75,523)
Payments on capital leases	(99,863)	(21,933)
Proceeds from exercise of stock options	10,132	34,048
Proceeds from exercise of Series E warrants		8,948
Proceeds from issuance of convertible note warrants		1,354
Proceeds from shares purchased under the stock purchase plan	167,721
Payments on NuvoGen obligation	(362,500)
Settlement of fractional common shares		(2,925)
Net cash provided by financing activities	1,783,008	51,095,229
Increase (decrease) in cash and cash equivalents	2,229,841	(1,015,249)
Cash and cash equivalents at beginning of period	3,293,983	3,613,392
Cash and cash equivalents at end of period	5,523,824	2,598,143
Noncash investing and financing activities
Accretion of preferred stock issuance costs		35,046
Accretion of dividends		1,165,932
Deferred offering costs reclassified to distributions in excess of capital		2,297,079
Allocation of Series E warrant convertible notes debt discount		741,828
Conversion of convertible notes and related accrued interest to common stock		4,544,384
Reclassification of convertible preferred stock liability warrants to equity warrants		(1,616,140)
Fixed asset purchases payable and accrued at period end	25,496	272,847
Stock issued for settlement of accrued bonus	(364,910)
Purchase of property and equipment under capital lease	226,835
Incentive from landlord	710,000
Supplemental cash flow information
Cash paid for interest	$ 850,713	701,250
Common Stock
Noncash investing and financing activities
Conversion of convertible preferred stock to common stock		(57,356,049)
Series D And E Redeemable Convertible Preferred Stock
Noncash investing and financing activities
Accretion of dividends		1,165,932
Series D and Series E Warrants
Noncash investing and financing activities
Exercise of warrants		(95,914)
Series E Warrants
Noncash investing and financing activities
Accretion of warrant discount		$ 127,616