Note 8 - Subsequent Events (Details Textual) - USD ($)			1 Months Ended			3 Months Ended
	Apr. 28, 2020	Apr. 21, 2020	May 12, 2020	Apr. 30, 2020	Feb. 29, 2020	Mar. 31, 2020	Mar. 31, 2019	May 14, 2020	Dec. 31, 2019
Class of Warrant or Right, Exercised During Period (in shares)						107,866
Proceeds from Warrant Exercises						$ 57,000	$ 5,000
Class of Warrant or Right, Outstanding (in shares)						1,608,200			1,716,066
Revolving Credit Facility [Member] | Boyalife Investment Fund II, Inc. [Member]
Proceeds from Long-term Lines of Credit					$ 1,869,000
Long-term Line of Credit, Total						$ 7,582,000
Interest Payable						$ 443,000	$ 461,000
Subsequent Event [Member]
Proceeds from Paycheck Protection Program Under CARES Act		$ 646,000
Subsequent Event [Member] | Conversion of Convertible Promissory Note into Common Stock [Member]
Debt Conversion, Original Debt, Amount				$ 188,000
Debt Conversion, Converted Instrument, Shares Issued (in shares)				104,445
Subsequent Event [Member] | Warrants Issused in Private Placement [Member]
Class of Warrant or Right, Exercised During Period (in shares)			263,216
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 6
Proceeds from Warrant Exercises			$ 1,600,000
Class of Warrant or Right, Outstanding (in shares)			626,821
Subsequent Event [Member] | April 2019 Pre-funded Warrants [Member]
Class of Warrant or Right, Exercised During Period (in shares)				224,445
Class of Warrant or Right, Outstanding (in shares)								0
Subsequent Event [Member] | Revolving Credit Facility [Member] | Boyalife Investment Fund II, Inc. [Member]
Proceeds from Long-term Lines of Credit	$ 2,418,000
Long-term Line of Credit, Total	10,000,000
Interest Payable	$ 580,000