SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

May 31, 2021

Accounting Policies [Abstract]

Schedule of Inventory, Current [Table Text Block]

	May 31, 2021		May 31, 2020
Raw materials	$	1,583,000	$	1,635,000
Work in progress		1,006,000		988,000
Finished products		617,000		228,000
Total	$	3,206,000	$	2,851,000

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2021	2020
Dividend yield	0%	0%
Expected volatility	71.19-107.53%	55.52-72.62%
Risk free interest rate	0.34-1.18%	0.43-1.80%
Expected Term	5.50-6.25 Years	3.75-6.25 Years

Disaggregation of Revenue [Table Text Block]

	Year Ended
	May 31, 2021		May 31, 2020
Clinical lab	$	3,077,000	$	2,922,000
Physician's office		2,801,000		2,195,000
Over-the-counter		766,000		1,270,000
Contract manufacturing		552,000		306,000
Lab supplies		3,000		-
Total	$	7,199,000	$	6,693,000