TCID50 Assay: A Simple Method to Determine Baculovirus Titer

There are many methods that can be used to determine the infectious titer of your baculovirus stock. The TCID50 method is a simple end-point dilution method that determines the amount of baculovirus virus needed to produce a cytopathic effect or kill 50% of inoculated insect cells. Serial dilutions of baculovirus stock are added to Sf9 cells cultivated in 96-well plates and 3–5 days after infection, cells are monitored for cell death or cytopathic effect. The titer can then be calculated by the Reed-Muench method as described in this method.