Development of Enhanced Reduced Representation Bisulfite Sequencing Method for Single-cell Methylome Analysis

Single-cell analysis provides molecular signatures to define cell identity. To characterize cell types, DNA methylation patterns are often used as a flag of internal molecular status. There are a few reports of single-cell methylome techniques that involves bisulfite conversion. However, the step often causes DNA fragmentation, which leads to severe PCR substrate reduction. Here we developed a new version of single-cell reduced representation bisulfite sequencing (scRRBS) method to recover more CpG sites to be analysed. Our method succeeded to increase of 4.1 times in sample yield and 1.6 times in CpG site coverage. Importantly, our results indicate that the obtained single-cell DNA methylation sites are homogeneous among 12 cells, thus it may provide molecular barcodes for cell types. In summary, we succeed to develop enhanced scRRBS method and it will be more useful tool to define cell identity in the near future.