title: High-yielding plasmid extraction method from acidophilic heterotrophic bacteria of the genus Acidiphilium.
abstract: Plasmid yield from Acidiphilium strains always had been poor following various standard methods. We adopted some simple modifications in the alkaline lysis procedure to get a better yield of plasmid from these bacteria. An approximately 10- to 20-fold increase in the plasmid yield was achieved when harvested Acidiphilium cells were preincubated 16-20 h at pH 6 in nitrogen-free medium. Another independent approach showed that freezing (-18 to -20 degrees C) of the harvested cells initially and at two subsequent steps in the alkaline lysis procedure of plasmid DNA extraction improved the yield further by 1.5- to 3-fold. The combination of these changes yielded at least 15- to 30-fold more plasmid from various Acidiphilium strains as compared with standard methods.
authors.affiliation: Indian Institute of Chemical Biology, Kolkata 700032, India.
authors.forename: Samarendra K
authors.initials: SK
authors.lastname: Singh
authors.forename: Pataki C
authors.initials: PC
authors.lastname: Banerjee
mesh_terms: D041801:Acidiphilium / Q000235:genetics*; D001483:Base Sequence; D004587:Electrophoresis, Agar Gel / Q000379:methods; D005615:Freezing; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics / Q000302:isolation & purification*; D013696:Temperature