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

8-Hydroxydeoxyguanosine (8-OHdG) is present in urine as a result of oxidati ve 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 u rine utilizing capillary electrophoresis with electrochemical detection (CE EC). The limit of detection for a aqueous standard of 8-OHdG is 50 nM (sign al 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 th e urine before analysis by CEEC. Optimized conditions for analysis of extra cted 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 be tween the ages of 23 and 43.