Why use PCR for testing gluten?

We often get the question: “Why do you have a gluten PCR in your portfolio?” A valid question indeed, because gluten is the general name for the proteins in wheat, barley, rye and triticale. Since PCR detects DNA or RNA – not protein, the question remains: How can you use qPCR in gluten analysis.

Of course, for the quantification of gluten in all types of food we recommend to use an ELISA based method, based on the R-5 antibody as in the RIDASCREEN® Gliadin (Art. No. R7001) test as mentioned in Codex standard CXS 118-1979. But sometimes that is not the end of the story, sometimes you need more answers. So, let’s take a closer look at the following situations:

• Confirmation of positive ELISA results:

Assume you have an unexpected positive ELISA result and would like to know if it is possible to confirm the presence of gluten containing cereals. With SureFood® ALLERGEN Gluten (Art. No. S3606) it is possible to detect the DNA of gluten containing cereals like wheat, rye or barley is present. So, this will give you an additional confirmation.

• Production of both gluten- and oat-free products:

Some products are both gluten free as well as oat-free. In that case SureFood® ALLERGEN Gluten (Art. No. S3606) is a good choice. This qPCR test detects the DNA of wheat, barley, rye and oat as well as other gluten containing cereals. Therefore, this qPCR test can be also used for the detection of gluten containing cereals as mentioned in the EU Food labeling legislation 1169/2011. For the detection of just oats in oat-free products or for testing production lines after cleaning we even offer a specific oat test: SureFood® Allergen Oat (Art. No. S7004)

• Further identification of gluten containing cereals:

Confirmation by PCR can be the first step, but it may be necessary to further drill down to identify the source of the contamination. Did your sample contain wheat, rye or barley or a combination of those? Which cereal type caused the positive results in your gluten test? Can you exclude a rye or barley contamination in your products? For all these questions SureFood® Allergen 4Plex Cereals (Art. No. S7006) is the right answer. In this multiplex PCR wheat, rye and barley are individually identified.The bottom line is that qPCR offers you additional information in quality management of gluten testing. qPCR can help you to confirm your results as well as to identify and find the source of contamination to assure the quality of your products. Please don’t hesitate to contact us for more details or other qPCR solutions!