The Cd-Chelex assay: a new sensitive method to determine metallothionein containing zinc and cadmium.
A rapid and sensitive one-vial procedure to determine metallothionein (MT) containing zinc (Zn) and cadmium (Cd) is described. New features of this Cd-saturation method are: high molecular weight Cd-binding proteins are denatured by treatment with acetonitrile (50% final concentration), and excess of Cd is bound to a cation exchange resin (Chelex-100). With this method, MT has been measured, e.g. in liver of control and zinc- or cadmium-treated rats, in human liver and in cultured human fibroblasts down to absolute amounts of 0.1 microgram. The Cd-Chelex assay is 10 times more sensitive than the established Cd-heme assay (Dieter et al. 1986) and therefore is particularly suitable to quantify MT in small tissue samples (e.g., liver biopsies of a few milligrams) and in extrahepatic tissues or cell cultures with low MT concentrations.
Institut für Toxikologie, Gesellschaft für Strahlen- und Umweltforschung, Neuherberg, Federal Republic of Germany.
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Bartsch
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Klein
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Summer
D000293:Adolescent; D000328:Adult; D000818:Animals; D002104:Cadmium / Q000032:analysis*; D002411:Cation Exchange Resins; D002478:Cells, Cultured; D002614:Chelating Agents; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007475:Ion Exchange Resins; D008099:Liver / Q000032:analysis; D008297:Male; D008668:Metallothionein; D011489:Protein Denaturation; D051381:Rats; D011919:Rats, Inbred Strains; D012117:Resins, Synthetic; D012680:Sensitivity and Specificity; D015032:Zinc / Q000032:analysis*
D002411:Cation Exchange Resins; D002614:Chelating Agents; D007475:Ion Exchange Resins; D012117:Resins, Synthetic; D002104:Cadmium; C024997:Chelex 100; D008668:Metallothionein; D015032:Zinc