Bac(ulovirus) in a Flash

Courtesy of Nextgen Sciences

NextGen Sciences of Cambridge, UK, http://www.nextgensciences.com has released a baculovirus expression system that reduces the timeline of recombinant virus production by up to 10 days, according to company literature. Key to the technology is a modified viral vector, called flashBAC, that lacks part of a gene (ORF 1629) essential for virus replication in insect cells, says company spokesperson Mark Littlewood.

A bacterial artificial chromosome (BAC) sequence allows the vector to propagate in bacteria. Homologous recombination by cotransfection of flashBAC and a transfer vector in insect cells removes the BAC sequence and produces an intact viral DNA containing a restored ORF 1629 sequence and the gene of interest. Thus only viruses containing the gene of interest can replicate.

Other systems produce a mixture of recombinant and parental virus and require a lengthy plaque assay to screen for viruses containing the gene of interest, says Littlewood. "With our technology, you only make 100% recombinant virus; there's no parental virus," says coinventor Linda King of Oxford Brookes University, Oxford, UK. "You don't have to separate the parental virus away from the recombinant virus at a later step, and therefore you would reduce all those time-consuming, labor-intensive steps."

NextGen licensed the technology from Oxford Brookes, which continues to sell the kit through Oxford Expression Technologies (http://www.expressiontechnologies.com. flashBAC is compatible with existing baculovirus transfer vectors, and comes in kit sizes ranging from four reactions ($360) to a 96-well plate version ($5,400).