Use of isolated cell preparations have been a powerful approach to understanding cellular and biochemical processes of a wide variety of tissues, including transporting epithelia. A method for isolating the extra-renal organ or salt gland from a larval brachiopod crustacean, the brine shrimp, has been developed. This preparation is unique as it is the first isolated epithelial cell preparation from a crustacean and is derived from an early stage of development. As both the removal and purification protocols differ markedly from previous cell isolation methods, details of their development have been described. This preparation has allowed measurement of the Na$K AT Pase specific activity in thesalt gland and intestine for the first time. Use of the isolated salt glands will facilitate cellular and subcellular studies of both the structure and function of this ion transporting epithelium.