Establishm ent of Polymerase Chain Reaction for Discrim ination of VaccineStrains of Canine parvovirus

Two pairs of PCR primers were designed according to the sequances of the vaccine strain andvirulent strain of CPV．Heminested PCR method was established．Result of the first PCR amplificationshowed the same am plified products of 574bp length ，after the second PCR am plification，the viru lentstrain produced the length 364bp fragment，but the vaccine strain couldn’t produce that．The products ofPCR were examined by electrophoresis an d restriction enzyme digestion．Th e result showed the lengthof the fragment an d enzyme sites were as the same as those designed．Th e PCR assay of CPV wasproved to be spec ific an d sensitive．It shows that this method may be used in discriminating the vaccinestrain an d viru lent strain of CPV or monitoring the vaccinated can ine in order to aviod disease andfinan ciallosing．