Testing for Gluten in Foods with Lateral Flow Devices: What’s the Scoop?

We talked a little bit about what ELISA tests are the other week. They’re great to use when testing for gluten in foods — if you have access to a very specific lab set-up and a lot of scientific know-how.

Now, there are definitely G12 ELISA tests, which use the same “magic ingredient” as GlutenTox does: the G12 antibody. However, when you use GlutenTox to search for gluten in your foods, drinks, personal care products, countertops, etc…you are not using an ELISA test, but a Lateral Flow Device!

What does Lateral Flow Device mean?

Well, it means that you get busy testing for gluten at home, or at the office, or anywhere really. And you don’t need any fancy equipment. It also means that you can’t find out only that Aunt Susie’s “gluten-free” cake have above/below the threshold of gluten that you choose to test for.

In other words, it’s qualitative not quantitative. Let’s imagine that Aunt Susie didn’t realize that spelt is not gluten-free, and her cake actually has 1000 ppm gluten in it. Whether you set your GlutenTox Home test to look for 5ppm or 20ppm, it’s going to show up positive (Phew, you’re safe from a bad glutening!). Now let’s imagine that Aunt Susie used good, GF ingredients but her wooden mixing spoon wasn’t quite clean — so the cake actually has 14ppm gluten. Your GlutenTox test will show positive at 5ppm, or negative at 20ppm, so depending on your sensitivity, you might choose to eat a slice and you might not. If you sent the cake to a lab to run a G12 ELISA, they could give you the specific amount of gluten in the cake.

testing for gluten in foods: lateral flow devices

A pregnancy test, but testing for gluten uses the same ideas!

So, how do Lateral Flow tests work when testing for gluten?

This slideshow uses a pregnancy test as the example, but the technology is essentially the same. There are a number of Lateral Flow tests on the market for home gluten detection, but for obvious reasons we’ll use GlutenTox as the example:

For a gluten test kit like GlutenTox, you first have to prepare your sample. Then the sample – liquid that contains tiny molecules of the cake, flour, soup, shampoo, whatever – gets dropped onto the plastic test stick.

It then flows laterally and picks up some new molecules the G12 antibody, plus some dye molecules and some other friends. The liquid keeps on moving down the strip, where it hits the Control and Test lines.

When the liquid hits the Control line, you see a blue line appear: this is the test’s way of telling you that it’s working. If you also see a pink line, it means that the G12 antibody got “stuck” on something in your sample and that, in turn, activates the dye and gets stuck on the Test line. If the test is negative, the pink dye won’t get stuck and you won’t see a pink line.

What is that “something” that G12 antibody sticks to? It’s the 33mer peptide of the alpha-gliadin molecule. In other words, GlutenTox is looking for the most toxic peptide of the most toxic molecule in wheat, barley, rye and oat.

Pretty neat, no? You can read more about lateral flow tests here, although the explanation here is not specific to testing for gluten in foods.


  1. What is the difference between ELISA and Lateral Flow testing? | GlutenTox - November 7, 2011

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