Density gradient fractions prepared from healthy or scrapie-infected hamster brain tissue enriched in plasma membrane vesicles were treated with nucleases prior to phenol extraction and ethanol precipitation. The recovered nucleic acids were 3' end-labelled and run on one-dimensional polyacrylamide gels. Autoradiography revealed the presence of low molecular weight RNAs (4S) in both healthy and scrapie samples. Two-dimensional fingerprint analysis indicated that the RNAs isolated from scrapie-infected hamsters contained oligonucleotides that were not present in RNAs isolated from healthy hamsters.