Development of an enzyme-linked immunosorbent assay for human metallothionein-1 in plasma and urine

The development of a sensitive enzyme-linked immunosorbent assay (ELISA) for human metallothionein-1 is reported. Metallothionein was purified from postmortem human liver and used to raise high-titer antibodies in rabbits. The assay was specific for human metallothionein-1 (MT-1), and there was no significant cross-reaction with human metallothionein-2. The detection limit (sensitivity) of the assay was 5 ng/ml, and the added MT-1 could be fully recovered from plasma and urine. The normal reference range for MT-1 was 32 +/- 16 ng/ml in plasma and 10 +/- 6 ng MT-1 per micromole of creatinine in random samples of urine. No significant differences were found between the values for males and females. The concentration of MT-1 was greatly increased between 24 and 48 hours after surgery, indicating that the protein behaves like an acute phase reactant in human subjects.