The passage of cells can improve the detection rate of avian leukosis virus to facilitate the elimination of avian leukosis in chickens

Avian leukosis (AL) is one of the most harmful diseases to the poultry industry in China. The detection of the avian leukosis virus (ALV) p27 antigen plays a decisive role in the elimination of avian leukosis. To explore the influence of passaging cells on the detection rate of the ALV p27 antigen, 21 aseptic anticoagulated blood samples were collected from 21 chickens for which the cloacal swabs were positive for the p27 antigen to inoculate two sets of cell culture plates containing DF1 cells. The cells were cultured for 4 d, one set was passaged, and the other set was not. After the DF1 cells had been cultured for 9 d, the ALV p27 antigen in the supernatants of the two sets was detected by ELISA. The results showed that the p27 antigen-positive rate for the passaged cells was 71.43% (15/21), higher than that of the cells that were directly cultured, which was 42.86%. There was a strong correlation, as high as 0.928, with respect to the S/P value of the p27 antigen in the supernatant between the two sets. In conclusion, there was a strong correlation between the results for the passaged and unpassaged cells, and the passage of cells greatly improved the detection of the p27 antigen.