Aberrations of the DNA methylome contribute to onset and progression of diseases. Whole genome bisulfite sequencing (WGBS) is the only analytical method covering the complete methylome. Alternative methods requiring less DNA than WGBS analyze only a minor portion of the methylome and do not cover important regulatory features like enhancers and noncoding RNAs. In tagmentation-based WGBS (TWGBS), several DNA and time-consuming steps of the conventional WGBS library preparation are circumvented by the use of a hyperactive transposase, which simultaneously fragments DNA and appends sequencing adapters. TWGBS requires only nanogram amounts of DNA and, thus, is well suited to study precious biological specimens such as sorted cells or micro-dissected tissue samples.