Estimation of baculovirus titer based on viable cell size.

In this paper, a simple and rapid protocol for determination of baculovirus titers based on increasing viable insect cell size/diameter following virus infection is presented. There are different methods available for determining virus titers such as plaque assays end-point dilution, quantitative real-time polymerase chain reaction and flow cytometry. However, most of these methods are time consuming and labor intensive. The titer estimation method presented here can be completed in approximately 28 h from start to finish. In this method, the Vi-CELL (Beckman Coulter) was used to measure cell diameter change over a range of virus dilutions, following infection. The cell diameter change data were used to compute the virus titer using a statistical method called the method of moments that we have described previously.