Figure 6. Schematic representation of the animals and samples used in study of preclinical detection of prions in blood of nonhuman primates infected with vCJD. The 72 m-vCJD samples previously analyzed by PMCA (Figure 5) were collected throughout the whole incubation period, starting 65 dpi until the final bleed. The first blood collection at 65 days postinoculation represents 759 (M1 and M2) and 644 (M3) days before the onset of the first neurologic signs. The 72 m-vCJD BC samples included 28 duplicates (represented as 2 circles in the timeline) and 4 quadruplicates (represented as 4 circles in the timeline). Open circles represent m-vCJD BC samples that were PMCA negative; dark circles represent m-vCJD BC samples that were PMCA positive. BH, brain homogenate; m-vCJD, macaque-adapted vCJD; PMCA, protein misfolding cyclic amplification; vCJD, variant Creutzfeldt-Jakob disease.