CELL-LINES USED FOR THE SELECTION OF RECOMBINANT BACULOVIRUS

Four insect cell lines were used to isolate two recombinant baculoviru ses which had the beta-galactosidase (beta-gal) gene for colorimetric assay purposes. Plaque assays were performed using two Trichoplusia ni cell lines: BTI-TN-SB1-4 and TN-368, and two Spodoptera frugiperda ce ll lines: IPLB-SF-21AE and SF9. The number of plaques (occlusion posit ive and blue beta-gal(+) recombinants) formed in the Trichoplusia cell s was higher than in the Spodoptera cells. The appearance of Autograph a californica NPV polyhedra was also faster in the T. ni cell lines. T he effect of cell passage on the plaque formation proved to be critica l when two different passages of the SF9 cells were tested. The higher passage produced a lower viral titration. The size and time of appear ance of the plaques was also different.