Assessment of Specific Binding Proteins Suitable for the Detection of Paralytic Shellfish Poisons Using Optical Biosensor Technology

• Published in: Analytical chemistry (Washington) Vol. 79; no. 15; pp. 5906 - 5914
• Main Authors: Campbell, Katrina, Stewart, Linda D, Doucette, Gregory J, Fodey, Terence L, Haughey, Simon A, Vilariño, Natalia, Kawatsu, Kentaro, Elliott, Christopher T
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-08-2007
• Subjects: Animals; Antibodies, Monoclonal - analysis; Antibodies, Monoclonal - immunology; Applied sciences; Binding sites; Biological and medical sciences; Biological Assay - methods; Biosensing Techniques - methods; Biosensors; Biotechnology; Brain Chemistry; Calibration; Carrier Proteins - chemistry; Carrier Proteins - metabolism; EU directives; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Global environmental pollution; Inhibitory Concentration 50; Marine Toxins - analysis; Marine Toxins - immunology; Methods. Procedures. Technologies; Optics and Photonics; Poisoning; Pollution; Proteins; Rabbits; Rats; Saxitoxin - analogs & derivatives; Saxitoxin - analysis; Saxitoxin - immunology; Sensitivity and Specificity; Shellfish; Shellfish - parasitology; Shellfish - toxicity; Sodium Channels - metabolism; Surface Plasmon Resonance - instrumentation; Surface Plasmon Resonance - methods; Toxins; Various methods and equipments; Performance evaluation; Chemical analysis; Bioassay; Immobilization; Biological indicator; Paralytic shellfish poisoning; Monoclonal antibody; Binders; Protein; Tissue; Toxin; Sodium; Biosensor; Standard curve; Poison; Feasibility; Surface plasmon resonance; Inhibition; Monitoring
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac070342o

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.