I read [Neil Mermelstein’s] article in the IFT magazine last February with great interest. Our laboratory does about 50% of the third-party gluten testing in North America (using the R5 ELISA method), and we work with many regulatory agencies on various allergen issues. … I have been working on gluten detection methodologies, starting with the Original Skerritt AOAC OM 991.19 method in 1992, but now have, in the past six years or so, moved on to the R5 and, more recently, the G12 (the A1 is also looking very promising).
I did notice an inaccuracy in your reference to AOAC Official Method 991.19, which does not refer to the R5 ELISA but the Skerritt ELISA. The Skerritt has fallen out of favor recently with the introduction of the R5 Ab by Mendez, because the Skerritt has fairly low sensitivity to Hordeins (~6%) as compared to wheat and rye.
As a matter of fact, we have developed a method which exploits this problem to differentiate barley contamination from wheat and rye contamination in foods. Last year, we presented our findings on this unique methodology for differentiating barley gluten from rye and wheat gluten at the AOAC meeting in Florida. We also published a paper on so called “gluten-free” grains (buckwheat, rice, soy, etc.) randomly selected from grocery stores, but many were found to contain high concentrations of gluten.
—Thomas Grace ([email protected]) , CEO, Bia Diagnostics LLC