Quantitative real-time PCR as an alternative to plaque assay titration for recombinant baculovirus expressing porcine parvovirus VP2 gene

Baculovirus expression system having post translational modification is used for large scale production of foreign proteins. Viral titre determination is crucial for efficient protein production. Even though plaque assay and end-point dilution method are conventionally used for titre determination, a less tedious and time-saving method is required for viral titre determination. Recombinant baculovirus expressing VP2 of porcine parvovirus was transfected in SF-21 insect cells. A quantitative real-time PCR was optimized for r-baculovirus titre determination and correlated with plaque assay method for its performance. The baculovirus DNA qPCR Ct values and corresponding PFU/mL showed strong correlation having value of r =99.71 at 95% confidence interval.