Selective precipitation of plasmid with a water‐soluble cationic surfactant

Abstract

Abstract The aim of the present study was the selective precipitation of plasmid directly from alkaline lysate produced from bacterial culture with the cationic detergent, N , N ', N '‐polyethylene (10)‐ N tallow‐1, 3‐di amine propane. Polyethylene groups of peg‐10 tallow were functionalized with tertiary amine groups and long alkyl chain. The functional groups of cationic detergent were determined by means of 1 H nuclear magnetic resonance (NMR) spectroscopy. A simple and efficient process for plasmid purification by cationic detergent was found to be dependent on acid concentration. The structure of peg‐10 tallow cationic detergent after adding acid solution was characterized using Fourier transform infrared (FT‐IR) spectroscopy. Inorganic acid such as HCl was introduced into the solution of peg‐10 tallow. Controlling pH of precipitation system by the addition of different concentrations of HCl acid solutions on peg‐10 tallow improved the partial separation of RNA from plasmid DNA (pDNA). However, different lysate masses were applied to observe the effect of 7.5% acid solution on the separation of RNA from pDNA with a peg‐10 tallow cationic surfactant. The results were realized by 1% agarose gel analysis. Copyright © 2009 John Wiley & Sons, Ltd.