PRNP and Creutzfeldt Jacob disease: While the detergent-soluble and monomeric PrPC from non-CJD brain homogenate was only detectable in the top fractions 1–4 (Fig. 2a, right side), the detergent-insoluble PrPSc aggregates from sCJD brain homogenate were mostly recovered in the bottom fractions 8–12 (Fig. 2a, left side) after sucrose gradient sedimentation.