Proteinase K (PK) treatment and electrophoretic separation showed that PrPres derived from scrapie infected PES (PESSc) cells—especially the two bands that represent the mono- and the diglycosylated form of PrP—had a higher molecular weight than PrPres derived from brain homogenates of BSE diseased cattle, from mice that were experimentally infected with RML scrapie or from the sheep scrapie isolate that had been used to infect the PES cells (Fig. 1C). Here, PRNP is linked to scrapie.