Optimization of gene transfer in cultured insect cells

The use of polybrene for the efficient transfection of cultured mosquito cells is described. Cells are transfected with purified plasmid DNA coding for a bacterial chloramphenicol acetyltransferase (CAT) gene regulated by sequences from a Drosophila heat shock protein promoter. The DNA is added to the cells in serumfree medium containing polybrene, which facilitates adsorption of DNA to the cell surface. Expression of the transfected gene is induced by subjecting recipient cells to heat shock conditions. CAT activity in lysates from transfected cells is assayed using a simple thin layer chromatographic procedure. Adaptation of the transfection protocol to other insect cell types is discussed.