TABLE 1.

Intraperitoneal inoculation of mice of different ages with ME7 scrapie, showing the proportion of mice that developed disease, mean incubation periods, and the proportion in which PrP^Sc was detected in spleen by immunoblotting

Age at inoculation (days)	Proportion of mice with clinical scrapie	Incubation period (mean ± SEM) (days)	Proportion of mice with detectable PrPSc in their spleensa
			70 d.p.i.	Terminal scrapie	Survivors
0-1	9/27b	334 ± 7	0/12	9/9	1/18b
10	28/28	308 ± 6	11/12	NT	NA
14	28/28	284 ± 6	12/12	NT	NA
29-46	29/29	305 ± 5	12/12	NT	NA

^aNT, not tested; NA, not applicable.

^bA total of 18 of 27 mice, referred to as survivors, remained free of clinical signs of scrapie beyond 550 d.p.i.; no TSE-related pathology was detected in their brains.