In order to identifiy the virus further , a set of double nested primers for canine coronavirus was selected . the primers were designed in s gene region from ccv including two pairs of primers : ccvfl - ccvrl , ccvf2 - ccvr2 . the first is a pair of outer primer , and can amplify a fragement of 1086bp . the second is a pair of inner primer . and can amplify a fragement of 515bp . using the nested primers , many ccv strains can be identificated including k378 , insave - l , ccv 1 - 71 etc . synthesizing this set of primers , we selected the panda ' s liver - tissue materials and some different passages of viral culture to amplify by rt - pcr , and all of them respectively gained two target fragements of 1086bp and 515bp , but the control cell did not 合成該套式引物,選擇大熊貓原代病料和病毒各代細胞培養物,經套式( nested ) rt一pcr擴增,可得到一與設計值5巧bp相符的dna片段,經bst一xl ( 590 , 1110 )酶切鑒定,證明該擴增片斷為特異性片段;回收大熊貓肝組織原代病料和細胞培養物第2 、 3 、 29代的ccvfz一ccvrz擴增片段,純化,送生物公司測序。