Detection methods of possible prion contaminants in collagen and gelatin

Summary.  We describe methods for the preparation of collagen and gelatin samples to detect possible prion contaminants using Western blotting of a major component of prions, PrP^Sc. A commercially available collagen solution containing 2% athero-collagen was spiked with rodent adapted scrapie prion and used as the prion-contaminating collagen. The methods developed center on the enzymatic reduction of the collagen solution viscosity with protease treatments and on the concentration of the prion from the protease-digests with polyethylene glycol-#6000 and NaCl. Recovery of the spiked prion as a partially protease-resistant core fragment of PrP^Sc fluctuated from 30% to 46% of the input amount. Received June 19, 1998 Accepted August 5, 1998