Abstract
A new method was developed to study transient gene expression, stable transformation, and cotransformation in suspension cells, such as mouse myeloma and erythroleukemia cells. This method involves attachment of cells to a concanavalin A-coated tissue culture dish, treatment of cells with DEAE-dextran to adsorb plasmid DNA to the attached cells, and finally treatment with a 40% solution of polyethylene glycol to facilitate the uptake of DNA by the cells. Plasmids pSV2cat and pSV2neo were used as markers to optimize the conditions for transient gene expression and stable transformation, respectively, of mouse myeloma and erythroleukemia cells. This method was successfully used to obtain cotransformants of mouse myeloma cells.