Figure 1. The effect of temperature on the desorption of ruminant PrPTSE bound to a sandy loam soil for up to 4 d. Scrapie (A and C) and BSE (B) prions were analyzed. PrPTSE was bound to soil either at 25–30°C, 8–12°C or 4°C as indicated. For individual soil columns, thermolysin-resistant prion was extracted in triplicate and the eluates from 100 mg of soil analyzed, each in duplicate, either by ELISA detecting full length PrPTSE (A and B) or by ELISA against an epitope within the 'core' of PrP and therefore measuring both full length and truncated PrPTSE (C). Standard deviations of the six replicate analyses of each column are shown. Each set of six replicates was compared by an unpaired, two-tailed Student's t-test. *p values derived by comparison of each data set to the data for prion recovery at 4°C; #p values derived by comparison of each data set to the data for prion recovery at 8–12°C.