e-Mag: How to choose the right allergen test kit?

When I started developing immunoassays for the detection of allergens in food, the first thing that struck me was the wide range of different food types or matrices that the assays had to work with…

Coming from a medical immunoassay background, there was a limited number of different matrices to work with. In my case, this was blood serum. With food there is an almost infinite range of different sample types, each with their own specific properties.

How do I choose the right test kit?

So how do we ensure that the test kit produced is suitable for use with such a diverse and challenging range of samples? This is where sample validation comes in. The process involves adding a known amount of an allergen of interest to our matrix (spike) and then trying to get that allergen back out again (recovery).

An important thing to remember is that, as the name implies, immunoassays use biological components (antibodies) to achieve the detection of the allergenic proteins of interest. As with all biological systems, the kits are sensitive to extremes.

In the case of foods, the kits may not work as they should in the presence of strong acid or alkali, high salt, high fat, etc. Many of these extremes can be countered during the extraction process. Kits therefore use a buffered system to cope with changes in pH and the addition of the buffer to the sample helps reduce and dilute some of the other problems such as salt and fat.