Rapid Detection of Botulinum Neurotoxin Activity in Food Matrices

Introduction: The mouse bioassay is the standard for botulinum neurotoxin (BoNT) detection in food samples in both government and industrial laboratories. While sensitive, the bioassay is low throughput, inaccurate, time consuming, and ethically challenging. Modern, biochemical methods are needed to replace animal-based methods for food challenge studies and food-related diagnostics. The BoTest™ Matrix Assays were developed by the detection botulinum of BoNT activity in complex matrices, offering sensitive, high throughput alternatives to current mouse bioassay methods.

Purpose: The assays were validated for the detection of BoNT in a range of food products including liquid and solid materials. These studies were used to establish the sensitivity of the assays in various matrices and to determine inter- and intra-assay variability.

Methods: BoNT/A, B, and F were spiked directly into food samples. Samples were then processed and subjected to the serotype-specific BoTest™ Matrix Assay. BoNT activity was quantified and results analyzed by BoNT serotype and food product.

Results: Limits of detection in 200 µL samples containing BoNT below 100 fM are possible with most tested matrices and below 10 pM for all sample types depending on the BoNT serotype and food product. Statistical analysis demonstrates intra- and inter-assay coefficients of variance below 10%. The assays were time-tunable and total assay times of less than 4 hours are possible depending on the desired sensitivity.

Significance: The BoTest™ Matrix Assays are rapid, robust, and high throughput alternatives to animal-based assays for BoNT potency testing and food challenge studies.