Fast isolation of recombinant baculovirus by antibody screening

A crucial step in the baculovirus expression system technique is the selection of recombinant viruses. In most cases positive clones, i.e., recombinant viruses, are detected via the presence of foreign DNA, or by exploiting the phenotypic differences between wild-type viral plaques, which are occlusion body positive, and recombinant plaques, which have an occlusion body negative phenotype (1 –4 ). Once a positive clone has been identified, the recombinant virus must be purified free from any wild-type precursor. A restriction analysis of isolated viral DNA might be necessary to determine whether the foreign gene has been correctly integrated. Having proven the presence of the gene, cells are infected with several independent recombinant viruses, in order to determine which of those gives the best expression of the protein in insect cells.