This kit provides a fast and simple method for determining titers of baculovirus stocks. The kit uses a standard immunological assay to accurately determine baculovirus titers within 48 hr, while plaque and end-point dilution assays typically require 5–10 days. In BacPAK Baculovirus expression systems, infected cells express viral antigens long before plaques are formed. The BacPAK rapid titer assay allows titer determination after a much shorter incubation period. Furthermore, the titers obtained are comparable to those obtained with other methods. This kit is suitable for use with any virus stock with a titer of more than 10⁴ pfu/ml and is compatible with all commonly available (AcMNPV-based) baculovirus expression systems.

The rapid titer immunoassay uses a primary monoclonal antibody raised against an AcMNPV envelope glycoprotein (gp64) to accurately identify virus-infected cells. A secondary HRP-conjugated antibody enables you to visualize infected cells by light microscopy and determine viral titer. Recently, we have improved the protocol to consistently offer our best ever signal-to-noise ratio for identifying cells.

BacPAK qPCR Titration Kit

This kit provides an extremely fast and simple method for titrating your viral stocks. The kit uses a quick DNA purification step before determining viral genome content using qPCR and green intercalating dye technologies. This titration kit requires only 4 hours and works with any AcMNPV-based baculoviral vector. Using qPCR enables you to perform viral harvest and target cell infection on the same day. You can avoid delays that lead to reduced viral infectivity and infect target cells at a known multiplicity of infection (MOI) for more consistent results.The BacPAK qPCR Titration determines the viral genome copy number in baculoviral preparations from a calibrated DNA standard curve. The procedure is simple: viral DNA and BacPAK control DNA are serially diluted and subjected to qPCR. The DNA copy number of each viral sample is then determined by comparing its C_t value to a standard curve generated by plotting the C_t values of the diluted control samples against their respective copy numbers.With its simplicity, reproducibility, and short processing time, the BacPAK qPCR Titration Kit is ideal for determining baculoviral DNA titers. Accurate and rapid titration provides the means to producing consistent results using high-quality viral supernatants in the shortest possible time.

Why you need to know your titer:

• Confirm the success of your packaging reaction to avoid wasting time with your experiments
• Perform consistent experiments
• Ensure sufficient MOIs such that 100% of your cells are transduced
• Control copy number and hence expression levels