COMPARISON OF THE SENSITIVITIES OF RIBONUCLEIC-ACID AND OLIGONUCLEOTIDE PROBES FOR INSITU DETECTION OF THEILERS VIRUS MESSENGER-RNA

To evaluate the sensitivity of in situ detection of the Theiler's viru s genome, we hybridized BHK-21-infected cells with anti-sense ribo- an d oligonucleotide S-35-labeled probes. The sensitivity achieved with t he anti-sense 280-nucleotide riboprobe was similar to that obtained wi th a 93-mer oligonucleotide probe. However, more reproducible and accu rate results were obtained with the riboprobe. With long exposure time s, the background was higher with the oligonucleotide probe than with the RNA probe. The background was improved by using freshly labeled ol igonucleotide probe.