AOAC ERP Gluten Assays - Dec 2018

Annex B

Abstract

The sandwich ELISA RIDASCREEN ® Total Gluten (R-Biopharm, R7041) employs a combination of four monoclonal antibodies including the R5 to detect intact (non-hydrolyzed) gliadins and related prolamins from rye and barley, High-Molecular Weight (HMW) Glutenin-Subunits (GS) from wheat, HMW-secalins from rye and Low-Molecular-Weight (LMW)–GS from wheat. Samples are extracted by Cocktail solution/80% ethanol and analyzed within 50 minutes. The measurement range is between 5 mg/kg gluten and 80 mg/kg gluten using a calibrator made out of a gluten extract from a mixture of four wheat cultivars. The system showed no cross-reactivity against 83 different food commodities. LoD was found to be between 0.4 mg/kg and 1.9 mg/kg for oat-based food. LoQ was verified at a level of 5 mg/kg. AOAC reference materials mentioned in SMPR ® 2017.021 showed recoveries between 86% and 131% for wheat and barley, while rye showed higher recoveries between 137% and 170%. Recoveries studies with incurred oat cookies and porridge revealed values between 55% and 122%. The precision of the whole procedure is mainly driven by inhomogeneity of samples which was proven by a precision of extraction experiment. A ruggedness study revealed no significant parameters for the extraction or ELISA procedure. The test kit is stable for at least 3 weeks at 37°C. The results of the in-house validation study confirmed that the method is accurate and suitable to measure gluten from all three grain sources with similar recoveries according to SMPR ® 2017.021.

Page 2 of 33

RIDASCREEN ® Total Gluten In-house validation report 2018-10-21