Measurement of DNA damage in individual cells using the Single Cell Gel Electrophoresis (Comet) assay

Methods Mol Biol. 2011;731:309-20. doi: 10.1007/978-1-61779-080-5_25.


The Single Cell Gel Electrophoresis (Comet) assay is a simple, versatile and sensitive method for measuring DNA damage in individual cells, allowing the determination of heterogeneity of response within a cell population. The basic alkaline technique described is for the determination of DNA strand break damage and its repair at a single cell level. Specific modifications to the method use a lower pH ('neutral' assay), or allow the measurement of DNA interstrand cross-links. It can be further adapted to, for example, study specific DNA repair mechanisms, be combined with fluorescent in situ hybridisation, or incorporate lesion specific enzymes.

MeSH terms

  • Cell Adhesion
  • Cell Line, Tumor
  • Comet Assay / methods*
  • DNA Damage*
  • DNA Glycosylases / metabolism
  • DNA Repair
  • Deoxyribonuclease I / metabolism
  • Humans
  • In Situ Hybridization, Fluorescence
  • Molecular Imaging
  • Single-Cell Analysis / methods*
  • Staining and Labeling


  • Deoxyribonuclease I
  • DNA Glycosylases