Abstract: This experiment was conducted to using a method of in situ hybridization to detect chicken neoplastic diseases. Three pairs of primers were designed and synthesized based on the published sequences of MDV,ALV-J and REV. The PCR amplified products were subcloned into pSPT-18 plasmid to generate DIG-labeled cRNA probes targeting MDV,ALV-J and REV respectively. Positive sections was hybridized with the three probes and the results showed good specificity and sensitivity.Thirty-two suspected neoplastic tissue samples from different farms were processed as paraffin-embedded sections and hybridized with RNA probes above. Of these samples, MDV, ALV-J and REV positive rates were 25.00%, 18.75% and 3.13% respectively. The study showed that chicken neoplastic diseases were still widely existed in the chicken farms.

Key words: in situ hybridization; cRNA probe; DIG; Marek’s disease; avain leukosis; reticuloendotheliosis