Note 11 - Grants and Collaboration Revenue (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue from Contract with Customer, Including Assessed Tax	$ 715,977	$ 364,232
Unused Grant Funds	606,944
NIH Grants [Member]
Revenue from Contract with Customer, Including Assessed Tax	654,021	354,319
Research Agreements [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ 61,956	$ 9,913