[Incorporation of plasmid DNA into liposomes from the total lipid of E. coli and determination of their stability].

Large monolamellar liposomes were constructed from the total E. coli lipid by ultrasonication and consecutive treatment with Ca2+ and EDTA. Serum albumin and plasmid DNA were incorporated into the liposomes with the efficiency of 6.3 and 4.7%, respectively. The plasmid DNA remained intact after incorporation, as was demonstrated by gel electrophoresis and transformation of E. coli with the DNA extracted from the liposomes, About one half of DNA-containing liposomes remained undamaged after 10 hr incubation at 4 degrees C. Possible implications of E. coli lipid liposomes in genetic transformation are discussed.