Frozen BAT was thawed and minced in 1% formaldehyde for 20 minutes at room temperature and quenched with the addition of 2.5M glycine. BAT was sonicated in (50 mM HEPES pH7.5, 155 mM NaCl, 1 mM EDTA, 1.1% Triton X-100, 0.11% Sodium-deoxycholate, 0.1% SDS) using probe sonication (30 sec on 30 sec off, 3 times at amplitude 10 then 30 sec on 30 sec off, 3 times at amplitude 15) at 4°C (Fischer Scientific, FB705 Sonic Dismembrator). Inputs were removed, and primary antibodies were added for overnight incubation at 4°C with rotation. NEBNext Ultra II DNA Library Prep Kit for Illumina.