A method for isolation of islets of Langerhans from the human pancreas.

A method has been developed for the isolation of islets of Langerhans from the human pancreas. The average number of islets isolated was 1011 islets per gram of pancreas (SD 475, range 752-2111), and the purity of the preparation as defined by histologic examination and specific staining for insulin varied from 10% to 40%. Islet structure was well preserved and the islets were shown to be viable by supravital staining, demonstration of insulin response to glucose, and by transplantation of isolated islets beneath the renal capsule of nude mice. The essential features of this technique for isolation of human islets include injection of a high concentration of collagenase (6 mg/ml) into the pancreatic duct under pressure, followed by a short incubation (23 min) at 39 degrees C. The gland is then dispersed by a process of teasing and shaking, and the islets are separated by a two-stage process of filtration on a nylon mesh to remove the larger islets and centrifugation on a preformed Ficoll density gradient to separate the small islets.