Preadipocytes are isolated from omental, mesenteric, or perirenal adipose tissue and are tested for their ability to differentiate in culture to mature adipocytes. Preadipocytes are available cryopreserved or plated and mature adipocytes are available in a variety of plated formats. Perirenal adipose resides near the kidneys outside the peritoneal cavity. Fat from this depot has not been correlated with increased risk for metabolic disease.