Oxford Expression Technologies (OET) has developed baculoQUANT™, a rapid quantitative PCR (qPCR)-based baculovirus titration system capable of accurately determining virus titres in under two hours. We use this validated method in-house to accelerate project timelines while ensuring consistent and reproducible protein expression by infecting insect cells at a precisely defined multiplicity of infection (MOI). For applications where qPCR is not suitable, we also offer plaque assay titration, the industry gold standard for determining the infectious titre of recombinant baculovirus stocks.
 

qPCR Titration​

The baculoQUANT™ assay quantifies baculovirus particles by first purifying viral DNA from freshly amplified budded virus. The purified DNA is then analysed by quantitative PCR using an ABI 7500 Sequence Detection System. Virus titres are calculated by comparison with calibrated reference standards that have been independently quantified by plaque assay. In our experience, baculoQUANT™ delivers results that closely correlate with traditional plaque assays while reducing turnaround time from days to just a few hours. For optimal accuracy, we recommend using freshly amplified virus stocks that are less than three months old.

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Plaque Assay Titration Service

For customers requiring a direct measurement of infectious virus, OET offers a fully optimised plaque assay service. This method determines the infectious titre of recombinant baculovirus stocks and is ideal for virus preparations where qPCR may not be appropriate or where plaque assay data is specifically required. In the plaque assay, cell monolayers are infected with a serial dilution of the virus stock solution and an agarose overlay is used to restrict the flow of virus. Cells that are infected release progeny virus, however, this only allows infection of neighbouring cells. Lysis of the infected cells produces clear regions or plaques. The plaques are then visualised using a dye such as neutral red.

 

Customers should provide a minimum of 0.5 mL of virus inoculum for either the baculoQUANT™ ALL-IN-ONE titration service or plaque assay.

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baculoQUANT™ ALL-IN-ONE Kit

For laboratories wishing to perform rapid baculovirus titration in-house, the baculoQUANT™ ALL-IN-ONE Kit is available to purchase through the OET online shop. The kit provides a fast, reliable and convenient solution for accurate baculovirus titre determination, enabling researchers to optimise expression experiments with confidence.