TABLE 4.

Recovery of infectious SV40 from cell lines established from hamster tumors

Virus	No. of tumor cell lines tested	No. of rescue-positive tumor cell lines	No. of SV40 genome copies/cella		Time to tumors (wk) from which cell lines were established
			Rescue-positive tumor cell lines	Rescue-negative tumor cell lines	Rescue-positive tumors	Rescue-negative tumors
SVCPC	12	1	ND	ND	16	14, 26, 27, 30, 32, 33, 35, 35, 37, 39, 39
Baylor(1E)	2	0		5.9, 326.3		21, 21
777	2	2	7.6, 16.8		21, 33
CPC-776	2	2	2.3, 23.4		20, 24
CPC-VA	2	1	17.3	3.4	22	30
CPC-PML	4	4	0.8, 0.9, 1.1, 4.9		25, 28, 30, 30
776(1E)	4	0		3.1, 6.4, 7.5, 10.8		29, 31, 33, 51
776(2E)	2	1	1.3	2.5	24	27
776-CPC	1	0		3.7		27
776-Baylor	2	1	2.8	13.7	21	17
776-VA	2	2	13.0, 33.4		26, 41
VA45-54	2	1	ND	ND	33	34
Total	37	15
Median		40b	4.9	6.2	25	30

^aND, not done.

^bShown as a percentage.