The Mendez R5 sandwich ELISA is the preferred method for laboratory analysis, except* for products consisting of, or containing, fermented or partially hydrolysed gluten:
- Codex Standard 118-1979: endorses the method as the preferred method of choice, thus has granted it Type 1 status.
- AOECS Standard for Gluten-Free Foods: stipulates that the analytical method to be used is the R5-sandwich-ELISA (Mendez-method)* and that it should be calibrated with the gliadin reference material from the Working Group on Prolamin Analysis and Toxicity (PWG-gliadin).