title: Effectiveness of natural and synthetic blocking reagents and their application for detecting food allergens in enzyme-linked immunosorbent assays.
abstract: Blocking is an important step before an enzyme-linked immunosorbent assay (ELISA) can be performed. It reduces non-specific binding to the microtiter plate to a minimum. For detecting food allergens by means of ELISA, the problem with protein blocking solutions is obvious. The blocker might interfere with the antibodies of the assay and leads to false positive results. Therefore, other blocking solutions are greatly needed. There are some alternatives like synthetic blockers or carbohydrates. Comparisons of these different blocking agents, namely proteins, carbohydrates, and synthetic blockers, were made at different reaction conditions. The incubation periods and temperatures were varied, as well as the pH. The best combinations were evaluated and compared, in respect of their blocking efficiency. The two best non-proteinaceous blockers, i.e. polyvinylalcohol and Ficoll, were subsequently applied to ELISA tests for the determination of alpha-casein and peanut. The study showed that Ficoll and PVA did as well as BSA in buffer solution. Therefore, they can be considered as alternative blocking reagents for ELISA, especially for the detection of food allergens.
authors.affiliation: Department of Agrobiotechnology, IFA-Tulln, Center for Analytical Chemistry, University of Natural Resources and Applied Life Sciences Vienna, Tulln an der Donau, Austria.
authors.forename: Denise
authors.initials: D
authors.lastname: Huber
authors.forename: Judith
authors.initials: J
authors.lastname: Rudolf
authors.forename: Parisa
authors.initials: P
authors.lastname: Ansari
authors.forename: Brigitte
authors.initials: B
authors.lastname: Galler
authors.forename: Manuela
authors.initials: M
authors.lastname: Führer
authors.forename: Christoph
authors.initials: C
authors.lastname: Hasenhindl
authors.forename: Sabine
authors.initials: S
authors.lastname: Baumgartner
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000276:immunology*; D001688:Biological Products / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005512:Food Hypersensitivity / Q000276:immunology*
chemical_list: D000485:Allergens; D001688:Biological Products