Establishing a limiting dilution of atypical PrPres in S05 brain material. S05 brain material was serially diluted up to 1013-fold, then each dilution was used to seed serial dgPMCAb; 18 serial dgPMCAb rounds were conducted and analyzed by Western blot. Ten serial PMCAb rounds were sufficient to amplify the highest dilution of brain material that still contains atypical PrPres (109-fold dilution) to the level detectible by Western blot. The reactions seeded with 1010-fold or higher dilutions were all negative regardless of the number of serial dgPMCAb rounds (Fig. 2c). Western blots were stained with SAF-84 antibody. (TIF 1376 kb
