title: Assessment of DNA damage by comet assay on frozen total blood: method and evaluation in smokers and non-smokers.
abstract: This study was undertaken with the aim to develop an optimised protocol for the evaluation of DNA damage in frozen whole blood. This was achieved by use of the single-cell gel electrophoresis (SCGE) or comet assay in its alkaline version. After collection of blood, the total blood sample was mixed with dimethyl sulfoxide (DMSO), a cryoprotectant commonly used for prevention of freezing-induced damage to living cells, and then stored at -80 degrees C. We observed no statistically significant differences in the level of DNA damage between fresh blood samples and frozen blood samples, as assessed by the comet assay. Considering the absence of effects of the freezing step, a frozen blood sample was included as a control sample in subsequent experiments. Thus the protocol was applied to blood samples of twenty healthy subjects including smokers and non-smokers. The comparative analysis indicated that the level of DNA damage was 56% higher in smokers than in non-smokers (P = 0.01). Altogether, this study strongly suggests that frozen whole blood could be utilised in association with the comet assay in human epidemiological bio-monitoring for the assessment of genetic damage in populations at risk.
authors.affiliation: L.B.S.O, Université Joseph Fourier, Grenoble, France. isabelle.hininger@ujf-grenoble.fr
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hininger
authors.forename: Alexia
authors.initials: A
authors.lastname: Chollat-Namy
authors.forename: Sylvie
authors.initials: S
authors.lastname: Sauvaigo
authors.forename: Mireille
authors.initials: M
authors.lastname: Osman
authors.forename: H
authors.initials: H
authors.lastname: Faure
authors.forename: Jean
authors.initials: J
authors.lastname: Cadet
authors.forename: Alain
authors.initials: A
authors.lastname: Favier
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Roussel
mesh_terms: D001769:Blood; D016022:Case-Control Studies; D020552:Comet Assay; D004249:DNA Damage; D005615:Freezing; D006801:Humans; D012907:Smoking / Q000097:blood*