A rapid and efficient method to enrich SAF-protein from scrapie brains of hamsters.

Scrapie hamster brains contain at least 5-10 micrograms of scrapie-associated fibrils (SAF) per brain as estimated by the amount of its major constituent, a protein of about 26 000 daltons (SAF-protein). It can be extracted efficiently by a 10% solution of sarkosyl and can be enriched by differential centrifugation and buffer extraction. Scrapie infectivity, SAF, and SAF-protein copurify.