title: Interlaboratory comparison of methodologies for the measurement of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine.
abstract: Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is widely used as a marker of oxidative stress. Here we report the comparison of two, distinct chromatographic assays with an enzyme-linked immunosorbent assay (ELISA). The chromatographic assays displayed good agreement (r =:0.89, p < 0.0001), whereas there was markedly worse, albeit still significant, agreement with the ELISA (high-pressure liquid chromatography followed by gas chromatography (HPLC-GC/MS), r = 0.43; HPLC with electrochemical detection (HPLC-EC), r = 0.56; p < 0.0001). Mean values differed significantly between the chromatographic assays and the ELISA (HPLC-GC/MS 3.86, HPLC-EC 4.20, ELISA 18.70 ng mg(-1) creatinine; p < 0.0001). While it is reassuring to note good agreement between chromatographic assays, this study reveals significant short-comings in the ELISA, which brings into question its continued use in its present form.
authors.affiliation: Department of Cancer Studies and Molecular Medicine, Radiation and Oxidative Stress Section, University of Leicester, Leicester, UK. msc5@le.ac.uk
authors.forename: Marcus S
authors.initials: MS
authors.lastname: Cooke
authors.forename: Lars
authors.initials: L
authors.lastname: Barregard
authors.forename: Vilas
authors.initials: V
authors.lastname: Mistry
authors.forename: Neelam
authors.initials: N
authors.lastname: Potdar
authors.forename: Rafal
authors.initials: R
authors.lastname: Rozalski
authors.forename: Daniel
authors.initials: D
authors.lastname: Gackowski
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Siomek
authors.forename: Marek
authors.initials: M
authors.lastname: Foksinski
authors.forename: Peter
authors.initials: P
authors.lastname: Svoboda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kasai
authors.forename: Justin C
authors.initials: JC
authors.lastname: Konje
authors.forename: Gerd
authors.initials: G
authors.lastname: Sallsten
authors.forename: Mark D
authors.initials: MD
authors.lastname: Evans
authors.forename: Ryszard
authors.initials: R
authors.lastname: Olinski