Purpose: This study was conducted to: i) develop a commercial, monoclonal antibody-based, direct sandwich enzyme-linked immunosorbent assay (ELISA) kit for the detection of gluten in complex food matrices; and ii) design an efficient extraction regime that eliminates hazardous waste issues associated with existing kits.
Methods: A new set of gluten-specific monoclonal antibodies, clones 13F6 and 14F11, were used to develop the MonoTrace Gluten ELISA. For maximum gluten extraction from various commercial and in-house incurred samples, extraction conditions were optimized to one hour at 60°C using a novel gluten extraction buffer (MGEB). Recovery of gluten using the MGEB (60% ethanol, sodium metabisulfite, and glutathione) was compared to the patented Mendez extraction cocktail, which contains a more toxic reducing agent, b-mercaptoethanol (BME), and guanidine hydrochloride (GuHCL).
Results: The newly developed gluten ELISA kit reduces the overall extraction time of gluten-containing products to a single step performed in one hour. Additionally, the requirement for toxic chemicals was eliminated, which negated the need for expensive hazardous waste disposal. Among the 47 tested commercial samples, with and without declared gluten, no false positive or negative results were obtained by the assay. This monoclonal antibody-based gluten sandwich ELISA demonstrated better than or equal recovery in 16 of 27 gluten positive samples, compared to the Mendez extraction method.
Significance: The new gluten ELISA from BioFront Technologies represents a sensitive and robust assay for detecting gluten in a wide variety of complex food systems, while utilizing a novel nontoxic extraction buffer.