Quantification of fish hepatic metallothioneins, naturally or artificially induced, by ELISA: A comparison with radioimmunoassay and differential pulse polarography

An ELISA has been developed for the quantification of metallothioneins (MT) in liver from different species of fish. MT has also been quantified by RIA and DPP to allow a comparison between the methods. The immunoassays were carried out with a polyclonal antibody raised against perch (Perca fluviatilis) hepatic MT [1] which cross-reacted with hepatic MT from dab (Limanda limanda), lemon-dab (Microstomus kitt), and cod (Gadus morhua). The ELISA was more sensitive for the detection of MT from the flatfish than RIA and DPP. The detection limits of MT by immunoassays were lower for fish caught in the field than for Cd-injected fish. The immunoreactivity differed between MT from different fish species, more markedly between fish MT and rabbit MT. MT values determined by the three methods have been compared and showed that the results were similar and significantly correlated. Advantages and disadvantages of the ELISA are discussed in relation to the other methods.