TABLE 2.

Detection of infectivity in cervical trunks of the vagus nerve by bioassays^a

Donor	Vagus nerve sample	Incubation time (days)		Estimated titer (ID50i.c./sample)b
		Range	Mean ± SE
S1	Left	119–292	162 ± 30	101.3
	Right	117–155	126 ± 7	102.7
S2	Left	117–239	144 ± 22	101.8
	Right	117–180	134 ± 11	102.3
S3	Left	120–260	151 ± 25	101.6
	Right	131–222	167 ± 18	101.3
S4	Left	131–183	159 ± 10	101.5
	Right	127–152	139 ± 4	102.0
S5	Left	124–242	153 ± 20	101.6
	Right	145–274	190 ± 21	<101.2

^aAliquots (50 μl) of homogenized left and right vagus nerves from terminally ill hamsters orally challenged with 263K were inoculated i.c. into groups of five recipients. Mortality was 100%. Recipients similarly inoculated with vagus nerves from donors previously orally mock infected with normal brain homogenate showed no clinical signs of scrapie. The experiment was terminated at 370 dpi. 

^bTotal amount of infectivity in one equivalent of excised tissue, i.e., the entire donor sample, calculated by applying mean incubation time to a dose-response curve.