design: We prepared bisulphite libraries based on the protocol described by Weichenhan et al (2019; Lymphoma: Methods and protocols, pp. 229248) with some modifications. We used 20-30 ng of DNA per sample. We performed tagmentation performed using in-house Tn5 transposase in ratios of 1:1 and 1:2 transposase to DNA. We used EZ-96 DNA Methylation-Gold MagPrep (Zymo, D5043) for bisulphite conversion. We did 13 or 15 cycles of PCR amplification for enrichment, and we used Illumina Nextera DNA indexes (i7/i5) to allow multiplexing. We performed size selection and PCR clean-up with in-house SPRI beads. We validated libraries by Fragment Analyzer Automated CE System (Advanced Analytical) and pooled them in equimolar concentration. Median insert size was around 350 bp. As an internal control, we added 5 pg of control DNA unmethylated Lambda (New England Biolabs, E7123A) per 10 ng sample DNA. Libraries were sequenced by the Next Generation Sequencing Facility at Vienna BioCenter Core Facilities (VBCF), on an Illumina NovaSeq Analyzer using manufacturers standard cluster generation ad sequencing tools (S2 flowcell with 100 bp paired end reads). To compensate for low nucleotide diversity in bisulphite libraries, each lane included a 15% splike in of phiX Control.