DNA was extracted using the AllPrep DNA/RNA kit from Qiagen. DNA was fragmented for 45 seconds using the Covaris E220 sonicator (10% Duty Factory, 175 Peak Incidence Power, 200 cycles per burst, milliTUBE 200µL AFA Fiber). The DNA was purified using 0.7 volumes of SPRISelect Beads (Beckman Coulter Life Sciences). To enable estimation of bisulfite non-conversion rates, a small amount of unmethylated lambda DNA was spiked in. The EZ DNA Methylation-Direct Kit (Zymo Research Corporation, D5020) was used to bisulfite convert DNA. Libraries were generated using the xGen™ Methyl-Seq Lib Prep Kit (IDT, 10009860) with combinatorial dual indexes as instructed.10-15 cycles of final amplification were used. Libraries were pooled and sequenced at the Genome Technology Access Center at the Washington University McDonnell Genome Institute on the NovaSeq 6000 2x150.