Establishment, verification and application of rapid detection of baculovirus infectious titer by flow cytometry

Titer detection of baculovirus usually is time-consuming. It is important to establish a rapid detection method for baculovirus titer. In this report, Staining of cells with a fluorescently labeled anti-gp64 antibody allows for identification of infected insect cells. By inoculating cultures with a series of log dilutions of virus, and staining of the cultures 13-22 h post inoculation, the ratio of infected to un-infected insect cells can be determined by flow cytometry(FCM). Statistical analysis of the percentage of infected cells in the virus dilution series enables accurate infectious titer determination. The culture time, cell growth state, the concentration of GP64-APC antibody and the concentration of inactivated FBS in diluent were optimized. The generality, repeatability and intermediate precision of the method were verified. The FCM method has the advantages of simplicity, accuracy, low cost and good repeatability.