library_construction_protocol: The distal forelimbs of embryos were dissected and placed into PBS with 10% FCS and 8ul collagenase at 50mg/ml (Sigma C9697) at 37º for approximately 5min. Cells were then washed three times in Wash Buffer with centrifugation steps in between at 300xg for 5 minutes each. After the CUT&RUN protocol, libraries were assembled with KAPA Hyper-Prep (07962347001)