Segment reporting (Details) - Schedule of segment reporting information, by segment - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Segment Reporting Information [Line Items]
Clinical laboratory services	$ 19,530	$ 18,837	$ 39,864	$ 37,395
Product revenues	7,122	6,983	14,203	14,409
Royalty and license fee income	300	440	561	740
Total revenues	26,952	26,260	54,628	52,544
Cost of clinical laboratory services	11,730	11,052	23,772	21,948
Cost of product revenues	3,877	3,520	7,266	6,829
Research and development	812	483	1,559	1,305
Selling, general and administrative	11,070	11,218	21,961	22,712
Provision for uncollectible accounts receivable	779	679	1,593	1,348
Legal fee expense	1,700	370	2,131	742
Operating income (loss)	(3,016)	(1,062)	(3,654)	(2,340)
Other	33	24	69	143
Foreign exchange gain (loss)	800	(94)	605	(455)
Share-based compensation	208	241	413	392
Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Share-based compensation	208	240	413	389
Cost of Clinical Laboratory Services [Member]
Segment Reporting Information [Line Items]
Share-based compensation		1		3
Clinical Labs [Member]
Segment Reporting Information [Line Items]
Clinical laboratory services	19,530	18,837	39,864	37,395
Total revenues	19,530	18,837	39,864	37,395
Cost of clinical laboratory services	11,730	11,052	23,772	21,948
Selling, general and administrative	6,107	5,897	12,202	11,849
Provision for uncollectible accounts receivable	800	594	1,600	1,260
Legal fee expense	8	49	21	101
Total operating costs and expenses	18,645	17,592	37,595	35,158
Operating income (loss)	885	1,245	2,269	2,237
Interest	(23)	(28)	(48)	(57)
Other	3	17	17	119
Income (loss) before income taxes	865	1,234	2,238	2,299
Depreciation and amortization included above	413	394	817	795
Capital expenditures	576	175	994	587
Clinical Labs [Member] | Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Share-based compensation	28	23	60	40
Clinical Labs [Member] | Total [Member]
Segment Reporting Information [Line Items]
Share-based compensation	28	24	60	43
Clinical Labs [Member] | Cost of Clinical Laboratory Services [Member]
Segment Reporting Information [Line Items]
Share-based compensation		1		3
Life Sciences [Member]
Segment Reporting Information [Line Items]
Product revenues	7,122	6,983	14,203	14,409
Royalty and license fee income	300	440	561	740
Total revenues	7,422	7,423	14,764	15,149
Cost of product revenues	3,877	3,520	7,266	6,829
Research and development	591	516	1,114	1,143
Selling, general and administrative	2,899	2,905	5,513	5,851
Provision for uncollectible accounts receivable	(21)	85	(7)	88
Legal fee expense	25	16	28	28
Total operating costs and expenses	7,371	7,042	13,914	13,939
Operating income (loss)	51	381	850	1,210
Interest	11	12	23	22
Other	1		8
Foreign exchange gain (loss)	800	(94)	605	(455)
Income (loss) before income taxes	863	299	1,486	777
Depreciation and amortization included above	355	501	681	1,009
Capital expenditures	28		72	102
Life Sciences [Member] | Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Share-based compensation	21	15	44	26
Life Sciences [Member] | Total [Member]
Segment Reporting Information [Line Items]
Share-based compensation	21	15	44	26
Therapeutics [Member]
Segment Reporting Information [Line Items]
Research and development	221	(33)	445	162
Total operating costs and expenses	221	(33)	445	162
Operating income (loss)	(221)	33	(445)	(162)
Income (loss) before income taxes	(221)	33	(445)	(162)
Other Segments [Member]
Segment Reporting Information [Line Items]
Selling, general and administrative	2,064	2,416	4,246	5,012
Legal fee expense	1,667	305	2,082	613
Total operating costs and expenses	3,731	2,721	6,328	5,625
Operating income (loss)	(3,731)	(2,721)	(6,328)	(5,625)
Interest	197	95	367	160
Other	29	7	44	24
Income (loss) before income taxes	(3,505)	(2,619)	(5,917)	(5,441)
Depreciation and amortization included above	18	20	37	38
Other Segments [Member] | Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Share-based compensation	159	202	309	323
Other Segments [Member] | Total [Member]
Segment Reporting Information [Line Items]
Share-based compensation	159	202	309	323
Consolidated [Member]
Segment Reporting Information [Line Items]
Clinical laboratory services	19,530	18,837	39,864	37,395
Product revenues	7,122	6,983	14,203	14,409
Royalty and license fee income	300	440	561	740
Total revenues	26,952	26,260	54,628	52,544
Cost of clinical laboratory services	11,730	11,052	23,772	21,948
Cost of product revenues	3,877	3,520	7,266	6,829
Research and development	812	483	1,559	1,305
Selling, general and administrative	11,070	11,218	21,961	22,712
Provision for uncollectible accounts receivable	779	679	1,593	1,348
Legal fee expense	1,700	370	2,131	742
Total operating costs and expenses	29,968	27,322	58,282	54,884
Operating income (loss)	(3,016)	(1,062)	(3,654)	(2,340)
Interest	185	79	342	125
Other	33	24	69	143
Foreign exchange gain (loss)	800	(94)	605	(455)
Income (loss) before income taxes	(1,998)	(1,053)	(2,638)	(2,527)
Depreciation and amortization included above	786	915	1,535	1,842
Capital expenditures	604	175	1,066	689
Consolidated [Member] | Selling, General and Administrative Expenses [Member]
Segment Reporting Information [Line Items]
Share-based compensation	208	240	413	389
Consolidated [Member] | Total [Member]
Segment Reporting Information [Line Items]
Share-based compensation	$ 208	241	$ 413	392
Consolidated [Member] | Cost of Clinical Laboratory Services [Member]
Segment Reporting Information [Line Items]
Share-based compensation		$ 1		$ 3