Analysis of Urinary 8-Hydroxydeoxyguanosine by Capillary Electrophoresis and Solid-Phase Extraction

Abstract

Urinary 8-hydroxydeoxyguanosine (8OHdG) has been considered as an excellent marker of individuals at high risk of developing cancer. Until now, urinary 8OHdG has largely been measured by high-performance liquid chromatography with electrochemical detection. A new method for the analysis of urinary 8OHdG by high-performance capillary electrophoresis has been developed and optimized in our laboratory. A single step solid-phase extraction procedure was optimized and used for extracting 8OHdG from human urine. Separations were performed in an uncoated silica capillary (50 cm  50 mm i.d.) using a P/ACE MDQ system with UV detection. The separation of 8OHdG from interfering urinary matrix components is optimized with regard to pH, applied voltage, pressure injection time and concentration of SDS in running buffer. The detection limit of this method is 0.4 mg/ml, the linear range is 0.8-500 mg/ml, the correlation coefficients levels is better than 0.999. The developed method is simple, fast and good reproducibility, furthermore, it requires a very small injection volumes and low costs of analysis, which makes it possible to provide a new noninvasive assay for an indirect measurement of oxidative DNA damage.

Recent developments in the determination of urinary cancer biomarkers by capillary electrophoresis

“…However, the concentration of 8-OhdG in urine is normally as low as 1-10 nM, which makes the detection difficult in most cases. Mei et al [98] tried to use a UV detector to determine urinary 8-OhdG after a one-step solid-phase extraction (SPE), but even after optimization of extraction conditions the detection limit only reached 0.4 mg/mL. The method mentioned above is still not sensitive enough for the extremely low concentrations of urinary 8-OhdG.…”

Capillary electrophoresis with end‐column amperometric detection of urinary 8‐hydroxy‐2'‐deoxyguanosine

“…Moreover, the HPLC-ECD method used previously for analysis of urinary 8OHdG often employed complicated and timeconsuming double or triple column switching [9,19,20] and two-or three-step SPE [9,19]. In a former study of our research group [21], CE with UV method was used to analyze urinary 8OHdG with good resolution. Because of the low sensitivity of UV detection, that method could not be used to determine the low concentration of 8OHdG in urine, which is reported to be in the range of 10 28 210 29 M. Compared with the CE-UV method, CE with electrochemical detection (CE-ECD) can provide greater selectivity and lower limits of detection.…”

Determination of urinary 8-hydroxy-2′-deoxyguanosine by two approaches—capillary electrophoresis and GC/MS: An assay for in vivo oxidative DNA damage in cancer patients

“…Since urinary 8OHdG has become increasingly popular as a sensitive, stable and integral marker of oxidative damage to DNA, several analytical methods, such as HPLC with electrochemical detection (HPLC-ECD) [17,20,21], gas chromatography (GC) [22,23], immunoassays [24], HPLC-MS/MS [25] and capillary electrophoresis (CE) [26,27] have been utilized for quantitative determination of urinary 8OHdG. Among these analytical methods, the highly sensitive and specific HPLC-ECD has been the most widely used method.…”