CONSOLIDATED BALANCE SHEETS - USD ($)	Apr. 30, 2018	Apr. 30, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 42,265,000	$ 46,799,000
Trade and other receivables	3,754,000	7,742,000
Inventories	16,129,000	33,099,000
Prepaid expenses	679,000	808,000
Assets of discontinued operations	5,000,000	1,426,000
Total current assets	67,827,000	89,874,000
PROPERTY AND EQUIPMENT:
Leasehold improvements	20,686,000	20,098,000
Laboratory equipment	10,258,000	10,229,000
Furniture, fixtures, office equipment and software	4,597,000	4,385,000
Construction-in-progress	3,310,000	2,841,000
Property and equipment, gross	38,851,000	37,553,000
Less accumulated depreciation and amortization	(12,372,000)	(11,508,000)
Property and equipment, net	26,479,000	26,045,000
Restricted cash	1,150,000	1,150,000
Other assets	304,000	1,043,000
TOTAL ASSETS	95,760,000	118,112,000
CURRENT LIABILITIES:
Accounts payable	1,909,000	3,000,000
Accrued payroll and related costs	2,564,000	5,055,000
Deferred revenue	10,922,000	28,500,000
Customer deposits	17,013,000	17,017,000
Other current liabilities	905,000	636,000
Liabilities of discontinued operations	4,550,000	8,723,000
Total current liabilities	37,863,000	62,931,000
Deferred rent, less current portion	2,159,000	1,599,000
STOCKHOLDERS' EQUITY:
Preferred stock - $.001 par value; authorized 5,000,000 shares; 1,647,760 shares issued and outstanding at April 30, 2018 and 2017, respectively	2,000	2,000
Common stock - $.001 par value; authorized 500,000,000 shares; 55,689,222 and 44,014,040 shares issued and outstanding at April 30, 2018 and 2017, respectively	55,000	44,000
Additional paid-in-capital	614,810,000	590,971,000
Accumulated deficit	(559,129,000)	(537,435,000)
Total stockholders' equity	55,738,000	53,582,000
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 95,760,000	$ 118,112,000