06 May 2010
DEVELOPING DETECTION METHODS FOR BIOTOXINS
Despite ethical concerns, for phycotoxin analysis in shellfish the reference method of analysis remains as the biological method or more commonly referred mouse bioassay. This is particularly the case for the global monitoring of diarrheic (DSP) and paralytic shellfish poisoning (PSP) toxins. The detection of the amnesic shellfish poisoning (ASP) toxin domoic acid is carried out by HPLC analysis and in recent years a laborious HPLC method has been developed for PSP toxin analysis. In FP6 several projects (Biotox, Biotoxmarin, Detectox, BioCop) were funded in the field of marine biotoxin analysis. Surface plasmon resonance (SPR) technology was displayed as a highly promising immunoassay based tool since it offers rapid real time detection requiring minimal reagents and standards due to the microfluidic system. The latter is essential because of the limited availability and supply of toxin standards. Alternative methods of detection to the biological methods have been described but to date each analytical method is specific for individual toxins and their immediate analogues with each group of toxins requiring individual tests. The ideal scenario for the monitoring of marine biotoxins would be to incorporate as many of the toxins onto a single assay format - one test fits all. Multiplexing can be achieved by the development of multi-flow cell SPR and/or by the development of multi-spots within a single SPR flow cell for different bio-recognitions. Within the scope of FP6 project BioCop a prototype 16-plex (4 spots x 4 flow cells) SPR instrument was developed for the detection of protein biomarkers. This device is a molecular interaction array system that can perform concentration analysis of multiple analytes. Within CONffIDENCE this technology is currently being applied to multiplex marine biotoxin analysis. A toxin assay for PSP (Saxitoxin), PSP (Neosaxitoxin), DSP (okadaic acid) and ASP (Domoic acid) toxins has been incorporated into each of the four flow cells of a single biosensor chip thus allowing samples to be analyzed under different cycle conditions. Toxicological studies on emerging toxins spirolides and palytoxins are on-going and these toxins will be incorporated onto the multiplex platform.
Information supplied by Chris Elliott, QUB, UK, Cluster 4 representative
Source : CONffIDENCE