Determination of phosphorus impurity that directly affects quantification of microbial genomic DNA using inductively coupled plasma optical emission spectrometry

Abstract

We prepared genomic DNA from human placenta, Escherichia coli, and Bacillus subtilis using various DNA extraction methods and quantified the genomic DNA using ultraviolet (UV) spectrophotometry, capillary electrophoresis (CE), and inductively coupled plasma optical emission spectrometry (ICP–OES). Application of ICP–OES unexpectedly led to a serious overestimation of phosphorus in B. subtilis genomic DNA prepared using cetyltrimethyl ammonium bromide (CTAB). Further investigations using reversed-phase high-performance liquid chromatography (RP–HPLC), ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC–ESI–MS/MS), and 31P nuclear magnetic resonance (NMR) identified the phosphorus impurity as lipoteichoic acid (LTA).