SIGNIFICANT ACCOUNTING POLICIES (Tables)

6 Months Ended

Nov. 30, 2021

Accounting Policies [Abstract]

Schedule of Inventory, Current [Table Text Block]

	November 30, 2021		May 31, 2021
Raw materials	$	1,416,000	$	1,583,000
Work in progress		708,000		1,006,000
Finished products		858,000		617,000
Total	$	2,982,000	$	3,206,000

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Option Shares	Exercise Price Weighted Average
Outstanding May 31, 2021	2,081,366	$	3.59
Granted	24,000		4.25
Exercised	(21,500)		1.64
Cancelled or expired	(24,750)		3.24
Outstanding November 30, 2021	2,059,116	$	3.62

Disaggregation of Revenue [Table Text Block]

	Three Months Ended November 30,				Six Months Ended November 30,
	2021		2020		2021		2020
Physician's office	$	3,359,000	$	153,000	$	3,616,000	$	351,000
Clinical lab		642,000		893,000		1,528,000		1,475,000
Over-the-counter		534,000		272,000		613,000		457,000
Contract manufacturing		112,000		55,000		152,000		233,000
Total	$	4,647,000	$	1,373,000	$	5,909,000	$	2,516,000