Effect of Polyethylene Glycol on Transfection of Escherichia coli Spheroplasts with Bacteriophage øX174 Single-stranded and Double-stranded DNAs

Abstract

The efficiency of transfection of Escherichia coli spheroplasts increased when polyethylene glycol was used as an osmotic stabilizer instead of sucrose. Optimal concentration of polyethylene glycol was 0.5 to 1.0% for transfection with bacteriophage øX174 single-stranded DNA and 1.0 to 2.0% for that with øX174 double-stranded replicative form of DNA, and the efficiency of transfection increased 4 to 7-fold under these conditions. The extent of transfection of the spheroplasts prepared in the presence of polyethylene glycol was proportional to the number of phage DNA added. The effect of polyethylene glycol on transfection was independent of the presence of protamine sulfate.