Development Of Rapid Immunoassay For Hg Cr And Pb

In this study,mercury,chromium and lead were selected as the research objects to prepare monoclonal antibodies and establish indirect competitive enzyme-linked immunosorbent assay?ic-ELISA?method and immunochromatographic strip assay based on the antibodies.To prepare the complete antigens,the 6-mercaptonicotinic acid?MNA?was used to couple methylmercury?MeHg?and the carrier proteins while Cr3+ and Pb²⁺ were coupled and the carrier proteins through the 1-?4-isothiocyanobenzyl?ethylenediamine-N,N,N',N'-tetraacetic acid?ITCBE?.By immunizing mice,cell fusion and antibody purification,three monoclonal antibodies were successfully obtained.The affinity of the three antibodies(anti-MeHg 2F8,anti-Cr3+-EDTA 1G8,anti-Pb²⁺-ITCBE 1G1)was very high and their subtypes were IgG2 b,IgG1 and IgG2 a respectively.The monoclonal antibodies were highly specific.Under optimum conditions,the half maximal inhibitory concentration?IC50?of CH3 HgCl,Hg²⁺,Cr3+-EDTA and Pb²⁺-ITCBE was 16.64 ng/mL,1.52 ng/mL,14.6 ng/mL and 1.99 ng/mL,while the limit of detection?LOD?was 5.27,0.354,3.89 and 0.632,respectively.The recovery rate of CH3 HgCl and Hg²⁺ in river water was ranged from 97.8%¹07.5% by the ic-ELISA.The recovery rate of Cr3+ in serum was ranged from 83.5%⁹0.65%.The recovery rate of Pb²⁺ in milk was ranged from 86.75%⁸9.5%.Based on the antibodies,the method of immunochromatographic strip assay was also developed.The cut-off level and LOD of CH3 Hg Cl in river water were 500 ng/mL and 20 ng/mL detected by the immunochromatographic strip assay.The cut-off level and LOD of Cr3+ in serum were 500 ng/mL and 50 ng/mL.The cut-off level of Pb²⁺ in milk,serum and urine were 100,100 and 50 ng/mL,while the LOD were 20,20 and 10 ng/mL,respectively.