DNA methylation is recognized as a principal contributor to the normal development and regulation of gene expression It is essential for maintenance of cellular identity and is associated with a number of key processes including genomic imprinting X-chromosome inactivation repression of transposable elements aging and carcinogenesis The current method to research DNA methylation is only bulk We combine the highly innovative single cell whole genome bisulfite sequencing WGBS library preparation and Illumina next-generation sequencing technology to visualize genomic methylation states at single-cell resolution It single cell whole genome bisulfite sequencing enables the discovery of cellular heterogeneity typically masked by standard bulk methylation sequencing We provide a streamlined workflow for making WGBS libraries Input DNA is randomly fragmented during the initial bisulfite treatment step followed by WGBS library preparation The procedure can accommodate ultra-low DNA input making it ideal for methylation analysis of precious limited and target-enriched samples CD Genomics provides single-cell DNA methylation analysis to understand the heterogeneity of genome-wide 5-methylcytosine 5mC patterns