Oil Red O and BODIPY Staining

After 8 days of differentiation, the intramuscular preadipocytes were stained with Oil Red O (#O0625, Sigma, USA) and 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY 493/503; D3922, Thermo Fisher Scientific). Oil Red O staining was performed according to the manufacturer's instructions. To quantify the staining of fat droplets, 100% isopropanol was used to dissolve the lipid droplets, and the absorbance was measured at 510 nm. For BODIPY staining, the cells were washed twice with PBS to remove residual 4% paraformaldehyde. Hank's Balanced Salt Solution containing 10 μM BODIPY 493/503 was added to the cells and then incubated at 37°C for 30 min in the dark. The samples were washed three times with PBS and photographed immediately.