|
Kathryn M. Ross1, Ian Garthwaite1, Christopher O. Miles1, Werner Fischer2, Daniel Dietrich2, A. Richard Chamberlin3,James B. Aggen3, & Neale R. Towers1,
1Toxinology & Food Safety, AgResearch Ruakura, 2 Department of Environmental Toxicology, University of Konstanz 3 Department of Chemistry, University of California, Irvine, Cyanobacteria (blue-green algae) capable of producing hepatotoxins, e.g. Microcystis spp. can be present in fresh water world-wide. These toxins, inhibit ser/thr protein-phosphatases, and induce hepatocyte necrosis/apoptosis. They are toxic to man, other mammals, and to fish-including salmonid species. This group includes the microcystin (MC) heptapeptides (over 50 known variants) and nodularin, a pentapeptide. Antibodies raised against a novel cyanobacterial toxin analogue-cBSA conjugate were used, together with ovalbumin-toxin-conjugates as a plate coater to develop a competitive ELISA. The ELISA is designed to detect most cyanobacterial hepatotoxins with equal sensitivity. It has a detection limit below 0.1 ng/ml, and a limit of quantitation lower than the WHO-proposed guideline (1 mg/l) for drinking water.. Water analyses can be performed without sample pre-concentration The assay shows good cross-reactivity with all microcystin analogues tested to date, and has ~100% cross-reactivity with nodularin (relative to MC-YR). The assay is robust and has been used successfully in the analysis of an array of aqueous matrices, including bloom samples collected from New Zealand lakes and rivers. The broad specificity of the ELISA makes suitable for use as a quick screening procedure for the detection of cyanobacterial hepatotoxins in water and the aquatic food chain.
|
