The in vitro alkaline comet assay (or single cell gel electrophoresis) can be used to detect DNA damage in the form of double strand breaks, single strand breaks, alkali labile sites and oxidative base damage. Biochemical techniques for detecting such forms of damage are combined with individual cell analysis familiar to cytogenetic assay approaches.
The assay name derives from the appearance of DNA-damaged cells after undergoing electrophoresis. DNA staining reveals a characteristic comet-like appearance: a bright ‘head’ (intact DNA) and a ‘tail’ streak (damaged and fragmented DNA). The length of the comet tail and the intensity of DNA staining within it are proportional to the extent of DNA damage. Performance of the assay under alkaline conditions increases its sensitivity for the detection of DNA single strand breaks, incomplete excision repair sites, cross-links and at sufficiently high pH alkali labile sites.
Comet Assay at Gentronix
Gentronix currently offers an alkaline in vitro comet assay as part of our genotoxicity testing service. The assay is performed in TK6 cells, with analysis conducted using Comet Assay IV™ software developed by Perceptive Instruments.
Gentronix comet assay testing services provides our clients with:
- Sensitive DNA damage detection.
- Low test chemical requirements.
- Analysis of 50 comets per test chemical dose.
- Typically 2 weeks from commencement of testing to results delivery.
- A cytotoxicity assessment to qualify the comet analysis.