Automatic detection of comets in Silver stained comet assay images for DNA damage analysis

Comet assay or Single Cell Gell Electrophoresis (SCGE) is a standard method for detecting Deoxyribo Nucleic Acid (DNA) damage in individual cells. The final stage of comet assay process is image acquisition and analysis. An effective automatic method for detecting comets from very noisy comet assay images is proposed in this paper. Most of the related work in this area are based on fluorescent stained comet assay images. But, silver staining method is commonly used for clinical applications in developing countries like India as it is inexpensive, slides can be preserved for a long time and is less hazardous. Currently most of the comet assay systems employ image analysis modules that are semi-automated which have the disadvantages of requirement of skilled personnel and having limited throughput. Hence, it is evident that a fully automated image analysis system is critical for rapid and accurate DNA damage detection. Therefore, an automatic comet detection stage as part of a fully automated comet assay image analysis system for DNA damage analysis and quantification is developed and implemented here. Based on our results and evaluation by a clinical expert, the performance of the proposed method is found to be better than that of the existing methods in terms of %TP, %FN, %FP, PPV and sensitivity.