A monoclonal enzyme-linked immunoassay for the detection of botulinum neurotoxin type E

Background and Aim: Botulinum neurotoxin Type E (BoNT/E), one of the most lethal toxin known, is the common contamination in fishery products or fish consumption that causes foodborne botulism. It is necessary to establish a sensitive and specific method for the detection of BoNT/E because of its extremely low lethal dose. Methods: In this study, a practical enzyme-linked immunosorbent assay for BoNT/E detection was developed. The assay is based on the sandwich format using monoclonal antibodies of two distinct specificities. An affinity-purified anti-BoNT/E light chain Mab (1E1) is utilized to adsorb BoNT/E from solution, and the second anti-BoNT/E heavy chain C terminus Mab (5E1) conjugated with peroxidase is then used to form sandwich complexes, and peroxidase allows color development and measurement of optical density at 450 nm. Results: Standard curves were linear over the range of 5–100 ng/ml BoNT/E. The limit of detection was below 10 ng/ml in phosphate-buffered saline buffer. The developed BoNT/E assay also showed no cross-reaction to Type A neurotoxin (BoNT/A) and Type B neurotoxin (BoNT/B). Conclusion: Herein, a sensitive and accurate ELISA for BoNT/E detection was presented. It has the potential to utilize in vivo BoNT/E analysis and contamination monitoring.