Figure 2. The effect of temperature on the desorption of scrapie PrPTSE bound to a sandy loam soil for 1 or 11 d. (A): PrPTSE was bound at 25°C or 4°C to soil that was either non-sterile (non-st) or sterile (st; autoclaved), as indicated. On day 1 and 11 thermolysin-resistant prion was extracted and the eluates from 100 mg of soil analyzed, each in triplicate, by ELISA detecting full length PrPTSE. Standard deviations of the three replicate analyses of each experimental condition are shown. The experiment was repeated twice more and gave equivalent results. (B) Representative samples were analyzed by western blot (10µl per lane, equivalent of an extract from 100 mg of soil), prion was detected with monoclonal antibody SHa31 (detecting a 'core' epitope) or SAF32 (detecting an N-terminal epitope) as indicated, and molecular mass markers are shown (M; 20, 30 and 40kDa). Both non-autoclaved and autoclaved samples gave equivalent results.