Assessment of Sperm Deoxyribose Nucleic Acid Fragmentation Using Sperm Chromatin Dispersion Assay

The integrity of sperm deoxyribose nucleic acid (DNA) is one of the determinants that ensure normal fertilization, implantation, pregnancy, and the generation of a healthy progeny. Assessment of sperm DNA fragmentation has gained importance as a tool to provide significant information regarding sperm quality, and it can independently predict sperm fertilizing potential. The sperm chromatin dispersion (SCD) assay is one of the available techniques to detect sperm DNA damage with results comparable to the gold standard - Sperm Chromatin Structure Assay. We present here a detailed methodology of an alkaline modification of SCD that can be carried out with minimal laboratory equipment. The SCD assay is a modified halo assay that utilizes chemical methods to demonstrate sperm DNA fragmentation. It involves the embedding of sperms in an agarose medium followed by exposure to alkaline denaturation and deproteinization. The results are interpreted under a light microscope. A visual scoring system is utilized to differentiate the sperms with possible DNA fragmentation from those without fragmented DNA and to determine the sperm DNA fragmentation index (SDFI) % for each semen sample. The SDFI % is directly proportional to the quality of sperm. The SCD assay is a simple, cost-effective, and reliable technique that can detect sperm DNA fragmentation, thus providing information regarding sperm functional quality and reproductive capacity. It is of significance in clinical and research areas of andrology and reproductive medicine, toxicology, and pharmacotherapeutics.