Abstract: Background: Bisulfite sequencing is the treatment of DNA with bisulfite before conventional sequencing to determine the methylation pattern. This method is the gold standard for DNA methylation detection. DNA methylation is an epigenetic modification in the genome and plays a vital role in embryonic development, cell proliferation, transcriptional regulation, and imprinting. Methylation mainly involves the addition of a methyl group to the 5-carbon position in the cytosine of CpG islands and represses transcriptional activity. Materials and Methods: In this review study, information related to bisulfite sequencing was searched and analyzed using the keywords Bisulfite Genomic Sequencing, Methylation, and Epigenetic Changes, through PubMed, Science Direct, Google Scholar, and Springer Link databases. Results: In this study, the history and various aspects of the bisulfite sequencing method, including its applications in biological research and new treatments for diseases, especially cancer treatment, have been discussed. Treatment of DNA with bisulfite converts cytosine residues to uracil but leaves 5-methylcytosine residues unaffected. DNA methylation, which often occurs at the C5 cytosine loop in CpG islands, is often found in gene regulatory sites such as promoters. Bisulfite sequencing uses conventional sequencing on bisulfite-treated DNA to determine the methylation status of CpG islands. Conclusion: Bisulfite sequencing can reliably determine DNA methylation changes in the desired DNA region, and in this way can help a lot in the investigation and diagnosis of various diseases, especially cancer. Keywords
