Figure 1. Amplification of macaque-adapted vCJD prions by PMCA. BH from 3 macaques peripherally infected with macaque-adapted vCJD was serially diluted and amplified by 3 rounds of PMCA, using BH from transgenic mice expressing human normally expressed prion protein with methionine at codon 129 (TgHu129M) as substrate. Human BH from a vCJD patient was analyzed as positive control. After completion of the 3 rounds of PMCA, samples were digested with 50 μg/mL of proteinase K and analyzed by Novex SDS-PAGE (https://www.thermofisher.com). N refers to transgenic mouse normal BH without proteinase K treatment, which was used as a migration control. BH, brain homogenate; PMCA, protein misfolding cyclic amplification; vCJD, variant Creutzfeldt-Jakob disease.