New segmentation methods of the comet assay images

The single cell gel electrophoresis, called Comet Assay is a microelectrophoretic technique of direct visualization of DNA damage at the cell level. In the comet assay, the cells suspended in an agarose gel on a microscope slide are subjected to lysis, unwinding of DNA and electrophoresis. After staining with fluorescent DNA binding dye, cells with DNA damage display increased migration of genetic material from the cell nucleus. Under the influence of weak, static electric field, charged DNA migrates away from the nucleus forming a so called comet. The damage is quantified by measuring the amount of the genetic material, which migrates from the nucleus to form the comet tail. The foremost advantage of the comet assay is that it analyses individual cells, thus allowing the measurement of the heterogeneity of response within a cell population. In this paper we present three novel methods of the comet tail and head extraction.