Development and Application of Highly Sensitive Anti-immune Complex ELISAs for Microcystins in Tap Water

• Published in: Food and agricultural immunology Vol. 12; no. 3; pp. 231 - 241
• Main Authors: Tsutsumi, T., Nagata, S., Yoshida, F., Ueno, Y., Harada, K.-I.
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis Group 01.09.2000; Taylor and Francis; Taylor & Francis Ltd
• Subjects: Anti-IMMUNE Complex Antibody; Biological and medical sciences; Environmental pollutants toxicology; Environmental Tumor Promoter; Food industries; Food toxicology; Fundamental and applied biological sciences. Psychology; Medical sciences; Microcystin; microcystins; Sandwich Elisa; Toxicology; Water; Drinking water; Toxin; Cyanobacteria; Bacteria; Monoclonal antibody; Method; Detection; Tap water; Biological contamination; ELISA assay; Immune complex
• ISSN: 0954-0105; 1465-3443
• DOI: 10.1080/09540100050140768

We developed an anti-immune complex (IC) ELISA applicable to direct determination of trace amounts of microcystins (MCs) in tap water. Comparison of two assay formats revealed that the use of anti-immune complex monoclonal antibody (MAB) in the coating step to trap anti-MC MABMC complexes improved the sensitivity as well as precision. The detection limit and quantitative range of the IC ELISA was 2 pg ml −1 and 2100 pg ml −1 of microcystinLR (MCLR), respectively, indicating the most sensitive of all the methods for detecting MCs reported to date. Additionally, the IC ELISA maintained good reliability through its quantitative range, as evidenced by low coefficients of variation (5.010.8 and 4.910.2% for intra- and interassay, respectively). The IC ELISA showed good cross-reactivity to microcystin-RR and microcystin-YR, suggesting major MCs found in the environment can be detected by this method. Recovery tests in which quantitative range of MCLR were added to tap water resulted in a mean recovery of 99%, with a mean standard deviation of 5.7%; therefore the IC ELISA performed well in the analysis of tap water samples. ELISA analysis of tap water samples collected in China and Japan revealed that, among 17 samples tested, two samples collected in China were positive for MCs at 4.914 pg ml −1 . These results suggest that the newly developed IC ELISA can be used to monitor trace amounts of MCs in tap water.