Detection of a urinary biomaker for oxidative DNA damage 8-hydroxydeoxyguanosine by capillary electrophoresis with electrochemical detection

Abstract

Abstract8-Hydroxydeoxyguanosine (8-OHdG) is present in urine as a result of oxidative DNA damage associated with age-related diseases such as cancer. In this report a method is presented for the detection of 8-OHdG in human morning urine utilizing capillary electrophoresis with electrochemical detection (CEEC). The limit of detection for a aqueous standard of 8-OHdG is 50 nM (signal to noise ratio S/N = 3). A single solid-phase extraction (SPE) step with a C18 column is used for sample cleanup and 20-fold preconcentration of the urine before analysis by CEEC. Optimized conditions for analysis of extracted urine are E app = 0.5 V vs. Ag/AgCl with 20 mM sodium borate/20% MeOH v/v, pH 9, as the background electrolyte, and a separation voltage of 22 kV. The concentration of 8-OHdG varied from 6 to 86 nM with an average value of 42 ± 26.9 nM for four healthy female and four healthy male subjects between the ages of 23 and 43.

Determination of urinary oxidative DNA damage marker 8-hydroxy-2′-deoxyguanosine and the association with cigarette smoking

“…It was found that when E d was 0.45 V, the working electrode showed a good stability and high reproducibility. The results agreed well with previous report by off-column CE-AD [31].…”

“…The limit of detection for an aqueous standard of 8OHdG was 4.3 nM (signal-to-noise ratio S/N = 3), which was 10-folds lower than that of the off-column CE-AD method reported by Weiss [31] (50 nM) and almost five-folds lower than that of our previous study [43] (20 nM) for analyzing 8OHdG. Since the concentration of a urine sample was increased 20-folds after the SPE step, the limit of detection for a urine sample was 0.22 nM.…”

“…A recent report [31] found that though zwitterionic buffers exhibit lower electrophoretic currents than borate or phosphate buffers, no resolution of 8OHdG from matrix interferences was observed with the three selected zwitterionic buffers. We investigated the effects of several other buffers, such as Na 2 CO 3 , Na 2 HPO 4 , Na-borate, and Na-acetate on the peak current (i p ) and theoretical plates (N).…”

“…Jin et al [30] detected bovine serum albumin in a serum sample. Weiss et al [31] reported 8OHdG could be quantified in urine by off-column end-column amprometric detection (CE-AD) with a detection limit of 50 nM. A recent study of our group [43] developed a simple end-column CE-AD method without complex decoupler, which showed usefulness in analysis of 8OHdG in urine.…”

Study of urinary 8-hydroxydeoxyguanosine as a biomarker of oxidative DNA damage in diabetic nephropathy patients

“…The limit of detection for an aqueous standard of 8-OHdG was 4.3 nM (S/N = 3), which was 10-fold lower than that of the off-column CE-AD method reported by Weiss and Lunte [25] (50 nM) and almost five-fold lower than that of our previous study [24] (20 nM) for analyzing 8-OHdG. Since the concentration of a urine sample was increased 20-fold after the SPE step, the limit of detection for a urine sample was 0.22 nM.…”