Expression plaque purification

The replicating virus gave rise to virus plaques that were picked 10-12 days later. Six clones were isolated from one round of plaque purification and screened for protein expression. One clone was selected, amplified on HEK 293 cells, purified by cesium chloride ultracentrifugation, and used for preparation of a Master Virus Bank (MVB). 

Alternative methods have been developed to obtain virus stocks without plaque purification for expression of recombinant proteins in infected insect cells. The Bac-to-Bac technology (Invitrogen, Thermo Fisher Scientific) avoids homologous recombination in insect cells by using site-specific transposition in E. coli. With this technology, recombinant bacmid-DNA is generated that is used to transfect insect cells. 

---