Damage effect of subacute formaldehyde on hepatocytic DNA in mice

  Objective   To explore the hepatocellular DNA damage aftersubacute formaldehyde exposure and the application of normalization as a statistic method to improve the reproducibility of single cell gel electrophoresis(SCGE, comet assay).

  Methods   Mice were respectively exposed to different concentrations of gaseous formaldehyde for 14 d, 6 h perday.SCGEwas performed to detect the DNAdamages.And normalization was used to discuss the reproducibility of SCGEassay.

  Results   Formaldehyde could induce different kinds of DNAdamages: formaldehyde caused significant DNAstrands breaks at concentrations of 0.5 and 1.0 mg/m³(P < 0.001)while crosslinks were induced at 3.0 mg/m³.

  Results   from normalization were in consistent with the formerresults and indicated that DNAdamages were enhanced with the increase of formaldehyde level.

  Conclusion   Formaldehyde was both a DNAstrands breaks and crosslinks agent to the hepatocytes in vivo, which may be one of the possible mechanisms of formaldehyde as a carcinogen.Normalization could improve the reproducibility of SCGEassay.