The centrifugation protocol efficiently separated PrPC from PrPSc, with the small amount of residual PrPC efficiently removed via proteolysis with 1 μg/ml protease (see Fig. 2B, compare PrPC from normal BH and PrPC+PrPSc from vCJD digested BH). This evidence concerns the gene PRNP and variant Creutzfeldt-Jakob disease.