Avian leukosis virus subgroup J (ALV-J) infections cause significant economic losses because of increased mortality, tumor production, decreased production, and cost for eradication. Current quantification methods for ALV-J expressed by TCID50 are difficult to determine because of the lack of cytopathic effect in cell cultures and non-specificity of currently available antigen-capture ELISA tests. In this study, a one-tube fluorescent probe based real time RT-PCR method was developed for quantification of ALV-J and compared with available quantification methods. Cell lysates with different TCID50s determined by cell culture and antigen capture ELISA (ag-ELISA) were used for one-tube real time RT-PCR using fluorogenic probe and quantitative competitive RT-PCR (QC-RT-PCR). The results of QC-RT-PCR and real time RT-PCR were highly correlated to the TCID50s determined by conventional culture methods. They were also very specific, sensitive, easy to perform, reproducible, and rapid compared with conventional methods. These RT-PCR based quantification methods of ALV-J viral RNA will be useful for virological and pathogenesis studies.
Bibliographical noteFunding Information:
Support for this work was provided by the United States Poultry and Egg Association. We thank Drs C. Baile and S. Gullicksen, Department of Animal Science in University of Georgia, for technical support with the ABI Prism 7700.
- Real time RT-PCR