Production of recombinant baculoviruses using linearized viral DNA

The classical method for making a recombinant baculovirus relies on homologous recombination in insect cells to replace a segment of the baculovirus genome with the corresponding segment from a transfer vector that has been modified to include a foreign gene. The frequency of this recombination is low; most of the input viral DNA molecules do not recombine with a plasmid DNA. Typically, only 0.1-2% of the progeny viruses are recombinant; hence, large numbers of plaques must be screened in order to find a few recombinant viruses. If linearized viral DNA is used in the cotransfection step, instead of the native viral DNA, which is circular, the proportion of progeny viruses that are recombinant increases to about 25% (1 ). This can greatly reduce the work involved in screening for recombinant viruses.