Abstract: | A simple procedure to obtain plasmid preparations, suitable for transfecting mammalian cell lines using a calcium phosphate co-precipitation technique, is described. The protocol is based on the purification of plasmid DNA by double gel-filtration chromatography on Sephacryl S-1000 and additional slight modifications to the original transfection procedure. The purity of plasmid preparation was verified by analytical methods. The resulting preparation efficiently transfected NIH-3T3 cells.The authors are with the National Center for Scientific Research, Molecular Biology Department, Biotechnology Branch, POB 6880, Havana, Cuba. |