By Adrian Rogers, Senior Research Scientist, Romer Labs
I recently noticed that a scientist in the UK was following me on Twitter, and with a little desktop detection found out that he creates ELISA tests, which are used by the food industry to help comply with government rules. He agreed to answer questions about his work. Henry Ehrlich
AAC: How did you end up doing allergen testing? Was it something you were drawn to purely intellectually, or do you have a personal connection to the allergy world?
Adrian: I still maintain that I do not know what I want to do when I grow up and I turn forty next month. The food allergen diagnostics industry is still quite small and the products are still pretty niche. Everyone knows or has worked with everyone else, so you could say that it is a little incestuous! Not to sound too pretentious but I have only ever been for one successful job interview, every other job I seem to have fallen into based on reputation. My first job in food allergen testing came about because I was moonlighting and helping out another company with some gel electrophoresis work, they had a position that had just become available, I had a quick chat with the boss, and the rest, as they say, is history!
AAC: Can you please explain the technology in lay terms? Can you also explain the concept of “spike” which I saw in your article?
Adrian: The main work horse in any food allergen testing lab is the Enzyme Linked Immunosorbant Assay (ELISA). The molecules used to detect the allergens are the same as found in the immune system, namely antibodies. Animals are sensitized against food allergens, a blood sample is taken and purified and the allergen-specific antibodies are used to form the basis of the test kit.
Below is an example as to how the ELISA works. In the case of allergen testing we tend to use a sandwich ELISA, whereby the allergen is captured between two antibodies, the second antibody is linked to an enzyme that produces a color change. The more allergen present the more intense the color change. As we run known amounts of allergen with the unknown samples we are able to quantify the allergen present in the samples being tested.
Life would be very boring if we all ate the same foods. There is an almost infinite variability in the makeup of the food we eat. While variety is the spice of life when it comes to meal time, this same variety can pose many challenges when it comes to analyze the foods we eat for allergens by immunoassay based methods.
Processing, pH, fat content, salt content, polyphenols can all influence the recovery of allergenic protein from a food matrix, which is why it is essential to validate an immunoassay method with a wide variety of different and challenging matrices.
Part of this validation process involves adding or “spiking” a known amount of allergen into a food and then seeing how much of that allergen we can recover when we test it. This helps us assess the suitability of the test for a particular food matrix. So for example if we know that we can only recover 50% of the peanut we added into a chocolate sample we can adjust our calculations accordingly.
AAC: Can you tell us who your customers are and how they use it? It seems to be instrumental in holding food manufacturers accountable for the allergen content of their products. How do they use them? How does Romer fit into the picture between regulators and consumers? Do you engage with both sides or are you middlemen? What would you like parents to know as they seek to feed their food allergic kids?
Adrian: We sell our testing kits to the food industry, public analysts, and private testing labs. The food industry use them to monitor and control potential allergen contamination during the production process. The public analysts and private labs use them either on behalf of the food manufacturers in terms of contract testing or for legal enforcement purposes. A recent example shows how allergen testing kits led to a restaurant owner being prosecuted for ignoring a potential allergen risk.
In effect, Romer supplies the tools that help ensure that food for sale is fit for consumption by the allergic consumer, that they can trust the allergen statements found on the food wrapper and provide a way for regulators to ensure that food manufacturers and caterers are legally compliant with regard to food allergen legislation.
AAC: We can see how testing is an important tool in regulatory enforcement at the restaurant level (example cited) Is there some instance where the work you did had a dramatic effect at the industrial level? A recall perhaps, or an overhaul of manufacturing and supply procedures?
Adrian: Here in the UK, as well as US, Austria and Singapore, Romer Labs run ISO accredited allergen testing labs so I cannot give out specific details, but yes this happens quite frequently. It is the nature of the job that we see an increase in samples during a food scare. Probably the latest scare that the industry as a whole faced was the issue of peanut and almond contamination in spices, which was reported in Allergic Living.
As it turned out some but not all of the almond contamination seen in the UK was due to mahaleb, a spice that is made from crushed cherry stones, which belong to the same botanical family as almond. Due to the fact that cherry stones and almonds are closely related this led to a false positive result with the almond-specific ELISA tests. More information about a solution to this problem can be found here. Suffice to say we are all continually learning and allergen detection methods are constantly evolving.
AAC: Some people think there ought to be tests for everything. Can you explain why it is so hard to develop them? I know there are many regulatory hurdles. But there are also technical hurdles. Can you explain some of what you face in your work as you envision new products and applications?
Adrian: The biggest driver for the development of new kits is legislation, here in Europe we have a list of 14 allergens that must be labelled. More information can be found here. So we try and make sure that we have a kit available for each of the 14 allergens plus all the different nuts. The one allergen missing from everyone’s immunoassay portfolio is celery/celeriac, so most labs currently use DNA methods for detection. The problem is due to the fact that it is difficult create antibodies that just detect celeriac proteins, they often cross react with lots of different vegetables, but this is something we are working on.
The other driver of course is money, the kits take time to develop, up to a year on average from start to finish and we have to make sure they are commercially viable. So if there is not much demand for testing a particular allergen then we have to consider if it is worth the investment to produce a kit.
The most crucial part of any immunoassay are the antibodies, which can take between 3 to 6 months to generate depending on what animal is used. Then we need to assess them for quality if they are not good enough, not able to detect the allergen at a low enough level, or cross-react to lots of other foods. Then we have to start the process again. Other considerations concern what type of antibody we use, polyclonal or monoclonal. Do we raise the antibody against a mixture of all the proteins found in a food such as peanut? Or do we raise against individual proteins? (Ara h 1, Ara h 2, Ara h 3 etc). What do we use to calibrate the kit? Whole peanut or peanut protein? You have to remember that currently there are no Certified Reference Materials for food allergen analysis so this all can get a bit tricky.
AAC: Could you look ahead and tell us about the future of this kind of testing? Will it lie in further refinement of the techniques you describe here or is can we look forward to a quantum leap in the technology?
Adrian: The next big thing that needs to happen is the standardization of allergen immunoassay testing methods. This open access article explains the issues far better than I can.
As I mentioned earlier there are no certified reference materials for allergen analysis. This issue is being addressed but in my view there is a need for the allergen testing industry to come together and iron out other issues such as standardizing reporting units and being more open with what proteins the assays actually detect.
In terms of technology the new kid on the block is LC MS/MS methods. These are still in the research stage but great strides are being made to refine the procedures especially within the iFAAM project, currently the world’s largest food allergen project. That is as long as you can afford the equipment of course, Mass Spectrometers are not cheap. The main advantage over immunoassay based methods is that you would be able to multiplex your testing, so instead of testing your food for one allergen at a time you can use this technology to test for all allergens at the same time.
One recent development that does concern me is the rise of consumer allergen-testing devices. The technology is very similar to what we currently use so I am aware of its issues and potential failings. No existing food allergen testing kit manufacturer would sell its products direct to the public for personal use due to the issues I have touched upon above. All methods must be thoroughly validated to be deemed fit for purpose. The problem with allergen contamination is that it is not always homogeneous throughout the food, but instead can be present in random hot spots. In the lab we follow strict testing protocols and take representative samples, something that is simply not possible if you are sitting in a restaurant about to eat a meal. I am worried that such devices may lead to a false sense of security for the allergic individual which unfortunately may have severe if not fatal consequences.
AAC: Thank you for your time.
Adrian Rogers has been with Romer Labs for 7 years in his role as a senior Research Scientist. He is responsible for research and development within Romer’s allergen competence centre based in the UK. Before joining Romer Labs he was an R&D Scientist for Tepnel Biosystems where he was involved in the development of ELISA and Lateral Flow immunoassays for the detection of food allergens. Adrian is a microbiologist by training and has 16-years of experience in the development of immunoassays, 14 years of which have been spent developing test kits for the detection of food allergens. Over the years he has been involved in a number of food allergy projects including EuroPrevall, an EU funded multidiciplinary integrated project which investigated the prevalence of food allergy across Europe. He is currently a member of the University of Manchester’s Food and Health Network allergy cluster and recently co-ordinated Romer’s contribution to an Innovate UK Knowledge Transfer Project with the University of Manchester looking at improving soya allergen analysis.