Specific endocrine tissue marker defined by a monoclonal antibody.

One of two mouse monoclonal antibodies (LK2H10) produced by hybridoma technology against a human endocrine tumor (pheochromocytoma) demonstrated specific immunoreactivity for 69 normal and neoplastic endocrine and tissues known to contain secretory granules. This immunoreactivity was specific, since other normal tissues, tumors from endocrine cells without granules, and tumors from other nonendocrine tissues were negative when tested with antibody LK2H10. The antibody reacted with human fetal adrenal medulla and human pancreatic endocrine cells and with adrenal medullary cells from monkeys and pigs. The antigen detected by antibody LK2H10 is associated with cytoplasmic secretory granules, has an estimated molecular weight of 68,000, and may be related to human chromogranin.