The monoclonal antibody 7C8 recognizes rat caveolin-1, a membrane protein of ~22 kDa. Caveolae are sphingomyelin/cholesterol-rich membrane domains first discovered as membrane invaginations on the surface of endothelial and epithelial cells. Caveolae are present in most cells, but are especially abundant in adipocytes. In addition to caveolins only two major protein components of caveolae were identified, namely the semicarbazide sensitive amine oxidase (SSAO) and the scavenger receptor CD36. Caveolin cycles between the plasma membrane and intracellular compartments via the endocytotic pathway. Caveolin is involved in the rapid intracellular transport of newly synthesized cholesterol from the ER directly to the caveolae. Caveolin plays an important role in multiple signaling pathways, molecular transport and cellular proliferation and differentiation. Caveolin binds to endothelial nitric oxide synthase leading to enzyme inhibition. Furthermore caveolin is a candidate tumor suppressor gene in many tumors. The specific functions of caveolin-1/caveolae are highly cell and context dependent.The monoclonal antibody 7C8 recognizes caveolin-1α as well as caveolin-1β, which are present in many tissues, like aorta, heart, muscle, lung, adipose white, brown and epidydimal fat. The monoclonal antibody 7C8 can be used to immuno-isolate caveolae.