Myocardial tissue contains cardiocytes, smooth muscle cells, endothelial cells, fibroblasts, and other cell types that have plasmalemma. The sarcolemma is the plasmalemmal membrane of cardiocytes and other muscle cells; it has a structure that is unique and includes a carefully regulated biochemical composition. The method of preparing sarcolemmal membranes from isolated adult cardiocytes, its biochemical characterization, and some of the types of studies that have been performed using these preparations will be reviewed in this chapter.