TABLE 2.

Statistical analysis of Am-A-FACTT results

Variation	Sample size (no. of animals)	Detection of PrPSc aggregates (fluorescent units)								P valuec
		Mean	SD	SE	Variance	CV	Min	Max	Range
Interassaya
Control animals	50	147.220	21.477	3.033	459.971	0.03	104	192	88
Infected animals	50	579.380	33.257	4.703	1,105.996	0.057	509	641	132	<0.0001
Intra-assayb
Control animals	50	145.320	18.984	2.685	360.385	0.131	113	189	76
Infected animals	50	569.200	37.908	5.361	1,437.02	0.067	504	685	181	>0.0001

^aFor intra-assay variations, blood samples from five noninfected control mice and blood samples from five infected and terminally sick mice were assayed individually by Am-A-FACTT. Each sample was assayed in 10 tubes (5 × 10 = 50). The background, which was the average of five samples using PrP^C−/− mouse brain homogenates as a substrate, was subtracted from the reading.

^bFor interassay variations, 10 normal and 10 infected samples were assayed by Am-A-FACTT on five different days.

^cP values were calculsted by paired Student t test.