Damage effect of subacute formaldehyde on hepatocytic DNA in mice

Objective To explore the hepatocellular DNA damage after subacute 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 per day.SCGE was performed to detect the DNA damages.And normalization was used to discuss the reproducibility of SCGE assay.Results Formaldehyde could induce different kinds of DNA damages:formaldehyde caused significant DNA strands breaks at concentrations of?0.5?and?1.0?mg/m~3(P0.001)while crosslinks were induced at?3.0?mg/m~3.Results from normalization were in consistent with the former results and indicated that DNA damages were enhanced with the increase of formaldehyde level.Conclusion Formaldehyde was both a DNA strands 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 SCGE assay.