Very little information is available concerning the relationship between metallothionein and disease in humans. Recently, investigators have used the Cd-heme method to measure metallothionein levels in human liver samples obtained from autopsy. This assay, however, is not sensitive enough to measure metallothionein in small tissue biopsy specimens. As an alternative, we report the development of a human metallothionein enzyme-linked immunosorbent assay (ELISA). This assay used high-performance liquid chromatography-purified human metallothionein-1 and purified sheep anti-human metallothionein-1 IgG. A limiting antigen coating concentration of 100 ng/ml and a minimal antibody dilution of 1:4000 were chosen. The sensitivity of the ELISA extended to 300 ng/ml (15 ng). The coefficients of interassay and intraassay variation were 15.4% and 4.2%, respectively. Human livers obtained from autopsy were assayed by this method and the values compared with values obtained by the Cd-heme method....