Calcium Phosphate Transfection of Eukaryotic Cells

Transfection of DNA into cells is an indispensible protocol in molecular biology. While plenty of lipid-based transfection reagents are commercially available nowadays, a quick, simple, efficient and inexpensive method is to transfect eukaryotic cells via calcium phosphate co-precipitation with DNA (Graham and van der Eb, 1973). The insoluble calcium phosphate precipitate with the attached DNA adheres to the cell surface and is brought into the cells by endocytosis. Calcium phosphate transfection has been optimized and widely used with many adherent and nonadherent cell lines (Jordan et al., 1996). Calcium phosphate transfection can result in transient expression of the delivered DNA in the target cell, or establishment of stable cell lines (the latter requires a drug selection process). This protocol is also widely used for co-expression of plasmids for packaging viruses. Efficiency of transfection can be close to 100% depending on the cell lines used. Here, a calcium phosphate transfection protocol is described using a GFP plasmid and the HEK293 cell line.