RIDASCREEN® Gliadin (Art. No. R7001) is a R5 sandwich enzyme immunoassay based on specific monoclonal antibody to celiac toxic amino acid prolamin sequences to determine gliadin as a measure of gluten in food.
It is applicable for the quantitative measurement of intact gliadin as a measure of gluten in unprocessed and processed matrices from important gluten-free food categories, including rice- and corn-based products, soy, starches, pseudo cereals, legumes, spices, juice, nut nougat crème, cream cheese, pesto, meat, vegetarian meat alternative, cookies, dessert, cake, fish, bread, candies, and potatoes. The sandwich ELISA quantifies intact gliadin from wheat and related proteins from rye and barley. This method is not accurate for quantification of fermented or hydrolyzed gluten.
Gluten is a mixture of prolamin and glutelin proteins present in wheat, rye and barley. Prolamins from wheat are named gliadins.
The use of gluten in foodstuffs is extremely common because of its useful effects on e.g. texture, moisture retention and flavor. However, gluten intolerance disorders like coeliac disease require a permanent gluten-free diet to avoid clinical symptoms. According to the Codex Alimentarius (CODEX STAN 118/1979) two categories for labeling of dietary food according to the gluten content exist:
1) “Glutenfree” = Food products, containing < 20 mg / kg gluten
2) “Very low gluten” = Food products containing 20 – 100 mg / kg gluten
The threshold of 20 mg / kg has been adopted by many national legislations in many countries. The Méndez method – a combination of R5 ELISA and a special, patented buffer (cocktail) for optimized extraction of gliadin from heat-processed and non-heated food samples – is the Codex Alimentarius recommended method for analysis of gluten in food. It is Codex Alimentarius type I method for analysis of gliadin/gluten. Categorization as type I method defines it as reference method. R-Biopharm is the only R5 ELISA manufacturer who offers the licensed Cocktail (patented) (Art. No. R7006 / R7016) and hence fulfills the requirements of the reference method to 100 %.
Furthermore, RIDASCREEN® Gliadin is in combination with the Cocktail (patented) the only R5 ELISA, which is AOAC Official Method of Analysis (OMA 2012.01). Applicability for analysis of principally all foods is an important requirement to function as Méndez method in the meaning of Codex Alimentarius. An international collaborative proficiency study with 900 samples from 19 variably processed foods from 16 food categories proved this suitability in 2020. Accordingly, RIDASCREEN® Gliadin received from the AOAC as first assay worldwide the status as Official Method of Analysis (AOAC OMA 2012.01) “in food” in 2021. A limitation on certain validated food matrices as usual for other AOAC approvals is not present any longer.
The RRIDASCREEN® Gliadin in combination with the Cocktail (patented) is not only Codex Alimentarius type I method and AOAC Official Method of Analysis. It is also revised and approved method of AOAC-RI, AACCI and ICC (see below “Certificates”).
Watch our video tutorials for sample preparation and test procedure with RIDASCREEN® Gliadin:
- Cocktail (patented)
- Cocktail ECO
- RIDA® Extraction Solution (colorless)
- Set of 3 processed Gliadin Assay Controls
- AOAC Official Final Action Method – OMA 2012.01
- AOAC-RI – PTM Certificate No. 120601
- AACCI – Approved Method 38-50.01
- ICC – Standard Method No. 182
|Test format||Microtiter plate with 96 wells (12 strips with 8 removable wells each)|
|Sample preparation||Homogenization and extraction|
|Incubation time||1 h 30 min
|LOD (Detection limit)||0.5 mg / kg (ppm) Gliadin (mean) or 1 mg / kg (ppm) Gluten
0.06 – 1.24 mg / kg (ppm) Gliadin* (*depending on matrix)
|LOQ (Limit of quantification)||2.5 mg / kg (ppm) Gliadin or 5 mg / kg (ppm) Gluten|
|Validated matrices||Rice- and corn-based products, soy, starches, pseudo cereals, legumes, spices, juice, nut nougat crème, cream cheese, pesto, meat, vegetarian meat alternative, cookies, dessert, cake, fish, bread, candies, and potatoes|
|Available application notes||
|Detected analyte||QQPFP epitope that occurs in α-/β-, γ-, and ω-gliadins; B-, C-, and γ-hordeins; as well as γ- and ω-secalins from wheat, rye, and barley|
|Evaluation||Microtiter plate spectrophotometer (450 nm)|