A. 3T3 L1 adipocytes were treated with or without 1µm isoproterenol or insulin for 30 min. Lipid droplets were isolated by ultracentrifugation. Total and lipid droplet-associated proteins were subjected to immunoblotting using antibodies against ATGL, perilipin, HSL, G0S2 and aP2. B. Immunofluorescence staining with anti-ATGL antibodies was performed to reveal localization of endogenous ATGL in 3T3-L1 adipocytes pretreated with or without 1 µM isoproterenol/0.25 mM IBMX for 30 min. Lipid droplets were co-stained with BODIPY 493/503. C. siRNA-mediated knockdown was performed by electroporating 3T3-L1 adipocytes with either control siRNA (Ctrl) or ATGL-specific siRNA (KD). 3 days later, cells were treated with or without 1 µM isoproterenol for 30 min followed by lipid droplets isolation. Total and lipid droplet-associated levels of ATGL, HSL, G0S2 and perilipin were analyzed by immunoblotting.