DNA was isolated from 1*10^6 sorted cells using DNeasy Blood and tissue kit (#69504 Qiagen) according to the manufacturer's instructions and fractionated using a Bioruptor. Bisulfite conversion of DNA was done according to manufacturers' instructions using EZ-DNA Methylation gold Kit (#D5005 Zymo Research). Quality of bisulfite treated DNA was assessed by RNA 6000 Pico Kit (#5067-1513 Agilent) on a Bioanalyzer 2100 (Agilent). Libraries of bisulfite converted DNA were prepared using Pico Methyl-Seq Library Prep Kit (#D5455 Zymo Research) according to manufacturer's instructions and the final concentration and quality of the libraries was assessed using Qubit™ dsDNA HS Assay Kit (#Q32854 Thermo Fisher Scientific) and High Sensitivity DNA Analysis Kit (#5067-4626 Agilent) on a Bioanalyzer. Duplexed libraries were sequenced on a NextSeq 500 (Illumina) using NextSeq 500 High Output v2 Kit (75 cycles; #FC-404-2005 Illumina).