Perilipins constitute a family of phosphoproteins, with the primary forms in adipocytes, perilipin / PLIN1 A and B, arising from alternative RNA splicing of a single gene to produce 57 and 46 kD polypeptides. The antiserum specifically targets perilipin / PLIN1 on the surface of intracellular storage lipid droplets found in various tissues and cultured cells. It does not react with other PLIN/PAT-family members like adipophilin (ADRP/PLIN2), TIP47 (PLIN3), MLDP, or OXPAT/PAT-1 (PLIN5).