Condensed Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activities
Net loss	$ (10,540,477)	$ (6,512,416)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	299,409	240,698
Accretion of discount on NuvoGen obligation	177,751	94,684
Bad debt expense (recovery), net	33,854	102,467
Provision for excess inventory	210,881
Amortization of deferred financing costs	32,938	0
Amortization of discount on term loan	89,032
Amortization of final payment premium on term loan	59,091
Loss on settlement of convertible notes	705,217
Amortization of discount on convertible notes	90,222
Share-based compensation	146,548	81,162
Change in redeemable convertible preferred stock warrant liability	239,683	56,322
Loss on disposal of assets	70,626	35,960
Changes in operating assets and liabilities:
Accounts receivable	213,090	199,646
Inventory	(937,160)	(190,090)
Prepaid expenses and other	(657,054)	(47,284)
Accounts payable	7	(336,799)
Accrued liabilities	(418,392)	(300,316)
Deferred revenue	(12,495)	(64,548)
Net cash used in operating activities	(10,197,229)	(6,640,514)
Investing activities
Purchase of property and equipment	(444,329)	(372,640)
Purchases of available-for-sale securities	(32,877,808)
Net cash used in investing activities	(33,322,137)	(372,640)
Financing activities
Proceeds from exercise of stock options	5,578	327
Draws on line of credit		750,000
Payments on NuvoGen obligation	0	(225,000)
Proceeds from exercise of E warrants	8,948
Deferred offering costs	(1,002,930)
Deferred financing costs	(75,523)
Payments on equipment lease	(14,622)
Proceeds from issuance of convertible note warrants	1,354
Proceeds from convertible notes	4,500,000
Proceeds from initial public offering	47,654,190
Net cash provided by financing activities	51,076,995	7,910,250
Increase in cash and cash equivalents	7,557,629	897,096
Cash and cash equivalents at beginning of year	3,613,392	1,815,289
Cash and cash equivalents at end of period	11,171,021	2,712,385
Noncash investing and financing activities
Accretion of preferred stock issuance costs	35,046	208,687
Accretion of Series D and E redeemable convertible preferred stock dividends	1,165,932	1,568,762
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
Fixed asset purchases payable at period end	244,350
Reclassification of convertible preferred stock liability warrants to equity warrants	1,616,140
Supplemental cash flow information
Cash paid for interest	467,500	26,135
Common Stock
Noncash investing and financing activities
Conversion of convertible preferred stock to common stock	57,356,049
Series D and Series E Warrants
Noncash investing and financing activities
Net exercise of Series D and Series E warrants	95,914
Series E Warrants
Noncash investing and financing activities
Accretion of Series E warrant discount	127,616	137,094
Series E Redeemable Convertible Preferred Stock
Financing activities
Proceeds from sale of preferred stock, net of issuance costs		$ 7,384,923
Noncash investing and financing activities
Net exercise of Series D and Series E warrants	$ 11,312