An introduction to the single cell gel electrophoresis assay: a technique resolving issues in forensic science

Abstract

Time since death (TSD) estimation is a crucial issue in death investigation. In majority of homicide/suicide cases deceased body recovered within the first 48 h, therefore, it is critically important to determine the time of death quickly and precisely. In the present scenario, TSD estimation still remains difficult even for experienced pathologists undertaken with extreme caution. After death numerous factors may be of cadaveric or environmental origin can influence the ‘normal’ rate of postmortem changes. Therefore, it could be more difficult to estimate longer TSD. However, these environmental influencing factors can also effect on DNA in the form of degradation, which start after 1–2 h of death. This DNA degradation could be work as molecular clock which help to estimate early TSD. Single-cell gel electrophoresis (SCGE), also known as the Comet assay, is the technique by which DNA degradation can be visualized and measured qualitatively as well as quantitatively. Using this assay not only early TSD estimated but many other challenges such as time since deposition of biological fluids, repair of genetic material from degraded biological sample could also be resolved. With the help of this paper an attempt was made to introduce a well-known cytogenetic technique that is SCGE assay, which could be a versatile technique for forensic science.