Several types of gluten tests are available; some are used commercially, and some are designed for consumer use. Some commercial tests are so sensitive they can detect as little as 5 ppm (parts per million). Several manufacturers of gluten-free products use them to ensure the purity of their foods.

Gluten home tests usually work a lot like a home pregnancy test: A series of lines appear on a small wand to give you a reading. To dissolve the gluten, you mix the food with some fluid in a tube. You then use a small comb to place the liquid in the wand, which is about the size of a large, flat pen. The liquid flows through a test “window,” and within about five minutes, lines appear to indicate whether the food contains gluten.

The home test can detect wheat, triticale, rye, and some amounts of barley. Sensitivity of the home kit is 75–100 ppm for most samples, and kits of the future likely will detect even lower levels.