The subcellular localization of testicular sulfogalactoglycerolipid. 
The subcellular localization of sulfogalactoglycerolipid in rat testicular germinal cells was determined.  The sulfolipid of young rats was labelled in vivo with Na235SO4.  Rat testis cell suspensions were prepared, homogenized, and centrifuged on linear, continuous, sucrose gradients.  The labelled lipid had the identical equilibrium density distribution pattern as alkaline phosphatase, an enzyme of the plasma membrane.  The pattern of the sulfolipid was different from the patterns of enzyme markers for the Golgi apparatus, lysosomes, mitochondria, and endoplasmic reticulum.  From these results, we conclude that sulfogalactoglycerolipid is located on the plasma membrane of rat testicular germinal cells.