Selective precipitation of RNA, supercoiled plasmid DNA, and open-circular plasmid DNA with different cationic surfactants

Precipitation of RNA and plasmid DNA in clarified lysate produced from a bacterial culture was studied using three cationic surfactants with a different number of alkyl groups in the hydrophobic tail and cationic head. All the precipitation mixtures contained 0.5M of NaCl. The results obtained indicated that selective precipitation was achieved when different types of cationic surfactants were used. In this study, trimethyltetradecylammonium bromide (TTAB) appeared to be a promising precipitant for precipitation of supercoiled plasmid DNA.