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Updated: May 11, 2026
A High-Throughput Comet Assay Approach for Assessing Cellular DNA Damage
Published on: May 10, 2022
Comet assay: a method to evaluate genotoxicity of nano-drug delivery system
Somayeh Vandghanooni1, Morteza Eskandani
1Research Center for Pharmaceutical Nanotechnology, Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
Introduction:
Drug delivery systems could induce cellular toxicity as side effect of nanomaterials. The mechanism of toxicity usually involves DNA damage. The comet assay or single cell gel electrophoresis (SCGE) is a sensitive method for detecting strand damages in the DNA of a cell with applications in genotoxicity testing and molecular epidemiology as well as fundamental research in DNA damage and repair.
Methods:
In the current study, we reviewed recent drug delivery researches related to SCGE.
Results:
We found that one preference for choosing the assay is that comet images may result from apoptosis-mediated nuclear fragmentation. This method has been widely used over the last decade in several different areas. Overall cells, such as cultured cells are embedded in agarose on a microscope slide, lysed with detergent, and treated with high salt. Nucleoids are supercoiled DNA form. When the slide is faced to alkaline electrophoresis any breakages present in the DNA cause the supercoiling to relax locally and loops of DNA extend toward the anode as a ''comet tail''.
Conclusion:
This article provides a relatively comprehensive review upon potentiality of the comet assay for assessment of DNA damage and accordingly it can be used as an informative platform in genotoxicity studies of drug delivery systems.
Insights
The comet assay, a sensitive method for detecting DNA strand breaks, is valuable for genotoxicity studies of drug delivery systems. It helps assess cellular toxicity induced by nanomaterials.
Area of Science:
- Biomedical Science
- Toxicology
- Nanotechnology
Background:
- Drug delivery systems, particularly those using nanomaterials, can cause cellular toxicity.
- DNA damage is a primary mechanism underlying nanomaterial-induced toxicity.
- The comet assay (single cell gel electrophoresis, SCGE) is a sensitive technique for detecting DNA strand breaks.
Purpose of the Study:
- To review recent research on the application of the comet assay in drug delivery systems.
- To evaluate the potential of the comet assay for assessing DNA damage in genotoxicity studies.
Main Methods:
- Literature review of drug delivery studies utilizing the comet assay.
- Explanation of the comet assay principle: embedding cells in agarose, lysis, alkaline electrophoresis, and DNA migration to form a 'comet tail'.
Main Results:
- The comet assay is widely used due to its sensitivity in detecting DNA damage.
- Comet images can arise from apoptosis-mediated nuclear fragmentation.
- The assay visualizes DNA strand breaks through the migration of relaxed DNA loops.
Conclusions:
- The comet assay is a powerful tool for evaluating DNA damage.
- It serves as an informative platform for genotoxicity assessment of drug delivery systems.
- This review highlights the assay's potential in ensuring the safety of nanomaterial-based drug delivery.
