Improvement and application of a competitive ELISA for detection of metallothionein in human urine.

[Objective]To improve and apply the competitive ELISA method for measuring human urinary metallothionein(UMT).[ Methods] Human metallothionein(MT)was isolated from an adult liver by SephadexG-75 and Sephadex G-50 chromatographic column,and then used to immunize Balb/c mice for preparing monoclonal antibody(McAb).The competitive ELISA was established with the McAb as the primary antibody.UMT was determined in 298 urine samples from university students.[Results] The detection limit of the ELISA was 9 ng/mL.The coefficients of variation for the within-running and between-running were 1.78%-6.72% and 5.45%-13.26%,respectively,while the recovery was 99.69%-107.25%.Before physical exercise,UMT concentrations of subjects were(10.58±5.62)ng/μmol Cr,while their UMT concentrations increased significantly after exercising,reached to(19.73±8.65)ng/μmol Cr.UMT levels in smokers(86.58±30.96)ng/μmol Cr were significantly higher than those in non-smokers(14.73±6.57)ng/μmol Cr.[ Conclusion] The competitive ELISA established was accurate and precise for measuring human UMT.The physical exercising and smoking influenced the UMT levels.