DNA methylation, a form of chemical modification of DNA, can effect the genetic expression without changing the DNA sequence. DNA methylation plays an important role in the maintenance of the function of normal cells, inactivation of X chromosome in female, stabilization of genome structure, embryonic development, development and progression of certain diseases such as tumer. EM-seq (... https://www.cd-genomics.com/epigenetics/resource-dna-methylation-detection-em-seq.html