Preparation of Specific Monoclonal Antibodies (MAbs) against Heavy Metals: MAbs That Recognize Chelated Cadmium Ions

详细信息    查看全文

• 作者：Xiaoxia Zhu ; Lina Xu ; Yang Lou ; Haini Yu ; Xia Li ; Diane A. Blake ; Fengquan Liu
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2007
• 出版时间：September 19, 2007
• 年：2007
• 卷：55
• 期：19
• 页码：7648 - 7653
• 全文大小：139K
• 年卷期：v.55,no.19(September 19, 2007)
• ISSN：1520-5118

文摘

Monoclonal antibodies (MAbs) were produced against chelated Cd²⁺. Since Cd²⁺ ions are too small to elicit an immune response, the metal was coupled to protein carrier (keyhole limpet hemocyanin, KLH) using a bifunctional chelator 1-(4-isothiocyanobenzyl)ethylenediamine N,N,N′,N′-tetraacetic acid (ITCBE). Several mice were immunized with this Cd²⁺–ITCBE–KLH immunoconjugate. Spleen cells of two immunized mice were fused with myeloma cells, and the resulting hybridomas were screened using protein conjugates with covalently bound metal-free ITCBE (ethylenediamine tetraacetic acid) or Cd²⁺–ITCBE. Four hybridoma cell lines that produced MAbs with high selectivity and sensitivity (Aa4, Aa6, Ac4, and Ba2) were expanded for further study. Cross-reactivities with other metals were below 1% except for Hg²⁺, which showed a slight cross-reactivity in competitive ELISA. These antibodies were used to construct competitive ELISAs for ionic cadmium; the IC₅₀ of the four antibodies (Aa4, Aa6, Ac4, and Ba2) were 10.59, 4.19, 29.45, and 6.63 µg/L, respectively. The detection range and the lowest detection limit for cadmium, using the Aa6 antibody, were 2.19–86.38 µg/L and 0.313 µg/L, respectively. Spike-recovery studies in tap and stream water showed that the most sensitive antibody can be used for cadmium detection in drinking water.