title: Assessment of specific binding proteins suitable for the detection of paralytic shellfish poisons using optical biosensor technology.
abstract: Paralytic shellfish poisoning (PSP) toxin monitoring in shellfish is currently performed using the internationally accredited AOAC mouse bioassay. Due to ethical and performance-related issues associated with this bioassay, the European Commission has recently published directives extending procedures that may be used for official PSP control. The feasibility of using a surface plasmon resonance optical biosensor to detect PSP toxins in shellfish tissue below regulatory levels was examined. Three different PSP toxin protein binders were investigated: a sodium channel receptor (SCR) preparation derived from rat brains, a monoclonal antibody (GT13-A) raised to gonyautoxin 2/3, and a rabbit polyclonal antibody (R895) raised to saxitoxin (STX). Inhibition assay formats were used throughout. Immobilization of STX to the biosensor chip surface was achieved via amino-coupling. Specific binding and inhibition of binding to this surface was achieved using all proteins tested. For STX calibration curves, 0-1000 ng/mL, IC50 values for each binder were as follows: SCR 8.11 ng/mL; GT13-A 5.77 ng/mL; and R895 1.56 ng/mL. Each binder demonstrated a different cross-reactivity profile against a range of STX analogues. R895 delivered a profile that was most likely to detect the widest range of PSP toxins at or below the internationally adopted regulatory limits.
authors.affiliation: Institute of Agri-Food and Land Use, Queen's University, David Keir Building, Stranmillis Road, Belfast, Northern Ireland, United Kingdom. katrina.campbell@qub.ac.uk
authors.forename: Katrina
authors.initials: K
authors.lastname: Campbell
authors.forename: Linda D
authors.initials: LD
authors.lastname: Stewart
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Doucette
authors.forename: Terence L
authors.initials: TL
authors.lastname: Fodey
authors.forename: Simon A
authors.initials: SA
authors.lastname: Haughey
authors.forename: Natalia
authors.initials: N
authors.lastname: Vilariño
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kawatsu
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Elliott
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000276:immunology; D001681:Biological Assay / Q000379:methods*; D015374:Biosensing Techniques / Q000379:methods*; D001923:Brain Chemistry; D002138:Calibration; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D020128:Inhibitory Concentration 50; D008387:Marine Toxins / Q000032:analysis* / Q000276:immunology; D055095:Optics and Photonics; D011817:Rabbits; D051381:Rats; D012530:Saxitoxin / Q000031:analogs & derivatives / Q000032:analysis / Q000276:immunology; D012680:Sensitivity and Specificity; D012758:Shellfish / Q000469:parasitology* / Q000633:toxicity; D015222:Sodium Channels / Q000378:metabolism; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*
chemical_list: D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D008387:Marine Toxins; D015222:Sodium Channels; D012530:Saxitoxin; C043405:gonyautoxin II