Testicular Endothelial Cells (TEC), located in the mesonephros, migrate in the developing embryo from the mesonephros to form the testis vasculature during the process of testis cord formation. The migrating endothelial cells are also essential because they initiate cord formation by creating partitions for the Sertoli and Germ cells. Recent studies have shown that disrupting testis vascular development blocks testis cord formation and thereby prevents proper structural development of the testis. In addition, studies suggest that testicular endothelial cells have similar properties to brain endothelial cells and contribute to the establishment of the blood-testis barrier (BTB). Cultured Human TEC (HTEC) are a useful in vitro model to understand vascular defects in testis dysgenesis and may provide new insight for treatment of male reproductive disorders. HTEC from ScienCell Research Laboratories are isolated from human testis. HTEC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HTEC are characterized by immunofluorescence with antibodies specific to vWF/Factor VIII and/or CD31 (PECAM1). HTEC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast, and fungi. HTEC are guaranteed to further expand for 5 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Endothelial Cell Medium (ECM, Cat. #1001) for culturing HTEC in vitro.