title: Development of two highly sensitive immunoassays for detection of copper ions and a suite of relevant immunochemicals.
abstract: Availability of highly sensitive assays for metal ions can help monitor and manage the environmental and food contamination. In the present study, a monoclonal antibody against Copper(II)-ethylenediaminetetraacetic acid was used to develop two sensitive ELISAs for Cu(II) analysis. Cobalt(II)-EDTA-BSA was the coating antigen in a heterologous indirect competitive ELISA (hicELISA), whereas Co(II)-EDTA-BSA-horseradish peroxidase (HRP) was the enzyme tracer in a heterologous direct competitive ELISA (hdcELISA). Both ELISAs were validated for detecting the content of Cu(II) in environmental waters. The ELISA data agreed well with those from graphite furnace atomic absorption spectroscopy. The methods of developing the Cu(II) hicELISA and hdcELISA are potentially applicable for developing ELISAs for other metals. The chelator-protein complexes such as EDTA-BSA and EDTA-BSA-HRP can form a suite of metal complexes having the consistent hapten density, location and orientation on the conjugates except the difference of the metal core, which can be used as ideal reagents to investigate the relationship between assay sensitivity and antibody affinities for the haptens and the analytes. The strategy of conjugating a haptenated protein directly with HRP can reduce the loss of HRP activity during the conjugation reaction and thus can be applicable for the development of ELISAs for small molecules.
authors.affiliation: College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhao
authors.forename: Tiegui
authors.initials: T
authors.lastname: Nan
authors.forename: Guiyu
authors.initials: G
authors.lastname: Tan
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cao
authors.forename: Shuo
authors.initials: S
authors.lastname: Sun
authors.forename: Zhaohu
authors.initials: Z
authors.lastname: Li
authors.forename: Qing X
authors.initials: QX
authors.lastname: Li
authors.forename: Baomin
authors.initials: B
authors.lastname: Wang
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000737:chemistry; D000915:Antibody Affinity; D000941:Antigens / Q000032:analysis / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D004492:Edetic Acid / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005618:Fresh Water; D006241:Haptens / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry*; D007120:Immunochemistry; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D014874:Water Pollutants, Chemical
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D002614:Chelating Agents; D056831:Coordination Complexes; D006241:Haptens; D014874:Water Pollutants, Chemical; D012710:Serum Albumin, Bovine; D003035:Cobalt; D003300:Copper; D004492:Edetic Acid; D006735:Horseradish Peroxidase