A highly sensitive competitive enzyme immunoassay of broad specificity quantifying microcystins and nodularins in water samples.
Microcystins (MCs) form a group of cyclic heptapeptides produced by common cyanobacteria (blue green algae) and cause both acute and chronic toxicity. For immunization purposes, an amino derivative of MC-LR was prepared before coupling to BSA. Among the different monoclonal antibodies produced, mAb MC159 was selected due to its broad specificity to develop a sensitive enzyme immunoassay (EIA). This method measures MC-LR, MC-YR, MC-LA, nodularins in a similar way and exhibits an important recognition (cross reactivity up to 69%) for Adda analogues. Using MC-LR as standard, the present EIA proved to be very sensitive with a limit of detection close to 10 fmol/ml, largely below the provisional guideline level for drinking water proposed by the WHO (1 pmol/ml for MC-LR). This assay showed a high accuracy (CV% < 12) and a high recovery rate for MC-LR in spiked surface water (up to 96.5%). Moreover due to its broad spectrum of recognition, this method allows a real quantification of the sum of MCs in water bloom and cyanobacteria culture samples. Indeed, in parallel analysis of these samples using HPLC, EIA shows a good relationship between both measurements while LC-MS/MS demonstrates the presence of different variants of MCs whose heterogeneity did not impair EIA measurement.
Khreich
Nathalie
N
CEA, iBiTecS, Service de Pharmacologie et d'immunoanalyse, Gif sur Yvette, F-91191, France.
Lamourette
Patricia
P
Renard
Pierre-Yves
PY
Clavé
Guillaume
G
Fenaille
François
F
Créminon
Christophe
C
Volland
Hervé
H
D000818:Animals; D000911:Antibodies, Monoclonal; D004784:Environmental Monitoring / Q000379:methods*; D007124:Immunoenzyme Techniques / Q000379:methods*; D051379:Mice; D052998:Microcystins / Q000032:analysis* / Q000737:chemistry; D010456:Peptides, Cyclic / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D052998:Microcystins; D010456:Peptides, Cyclic; D014867:Water; C063998:nodularin