The monoclonal antibody G-81 recognizes a fragment of human dermcidin (DCD). The antibiotic peptide dermcidin (110 amino acids) is specifically and constitutively expressed in the sweat glands. DCD is localized to the dark mucous cells of normal eccrine sweat glands. DCD is normally expressed in eccrine sweat glands and is expressed in cutaneous mixed tumours. DCD-immunopositive cells are expressed in the inner cells of the tubular and ductal structures.The monoclonal antibody G-81 was produced against a sweat-specific antigen. It reacts to sweat but not to other body fluids (e.g. serum, saliva, semen, milk, urine and tears) in ELISA. The N-terminal amino acid sequence (18 amino acids residues) is identical to a part of human cachexia-associated protein and of a survival-promoting peptide for neuronal cells. Besides this, the sequence is identical to the C-terminal peptide (amino acids 62-79) of DCD. The monoclonal antibody G81 can be used as a specific marker for eccrine glands in the human skin.The monoclonal antibody G-81 is useful as a immunohistochemical tool to find the tumour cells that differentiate towards eccrine secretory cells in cutaneous mixed tumours. Furthermore, the antibody can be used for the detection of biochemical and histochemical changes of the sweat gland in the healing process of wound.