Taking Control of Allergens through Regulation

PCR utilizes a pre-designed sequence of foreign genes and a specific primer set, in the presence of DNA templates, DNA polymerase, dNTPs and magnesium ions, under specific conditions, finish denaturation, annealing and extension steps. After around 30 cycles, the sequence of foreign genes will be greatly amplified. Finally, DNA amplicons will go through electrophoresis and the DNA fragment will be easily detected. Therefore, with only a small amount of sample, PCR can accurately detect for the presence of DNA. Real-time PCR, which provides convenient and fast automated result analysis, can also achieve higher sensitivity and specificity than the traditional immunological testing and is another option for even more sensitive results.

Which One?

Of the two technologies discussed with regards to food allergen testing, DNA testing is the better choice due to its sensitivity and accuracy. Only a tiny amount of allergen DNA is needed for detection, which is important because the law currently imposes a zero tolerance limit for food allergen levels in food samples. Unlike ELISA, DNA testing does not give false positive results, which could be due to cross reactivity in ELISA, and false negative results, due to low sensitivity of ELISA, and can detect for allergens even if the food is cooked or processed.

Thus, DNA testing is a good method to detect food allergens and this advanced method is now widely accepted as being at a mature stage.

DNA Testing: The Concrete Foundation for a Food Allergen Management System

As more countries begin to implement tougher regulations governing the labeling of allergens on food products, the global food industry will find itself under more pressure to ensure the integrity of its products, as well as to effectively communicate this information to their customers. To do this, companies will need to systematically implement more robust food allergen management systems, of which a crucial part will be testing. While there are currently two main technologies for doing this, the traditional protein approach does not always result in dependable outcomes, nor can it be applied to every food. Thus, there is a need for us to explore more advanced methods such as DNA testing, which could be more sensitive, accurate and reliable, even with small sample sizes, and with processed foods, as an alternative or backup. It could serve as a tool to help lower the incidences of unintended allergic reactions, and help prevent the many emergencies and fatalities caused by proper food labeling. An appropriate strategy will allow food companies to guarantee their products, effectively meet regulations, and ensure the health and safety of their customers – thus not only building a responsible reputation as a caring corporate citizen, but also resulting in a safer global food supply.

References:

1. The Food Allergy & Anaphylaxis Network: New Research Shows Potential for Food-Allergic Reactions from Kissing. http://www.foodallergy.org/press_statements/kissingresearch.html
2. AAAAI. 2000. The Allergy Report. Milwaukee, WI: American Academy of Allergy Asthma and Immunology.
3. The Food Allergy & Anaphylaxis Network: Food Allergies Now Believed to Affect 1-in-25 Americans According to FAAN Study Released at AAAAI Annual Conference, Americans with Seafood Allergies More Than Double Those with Peanut Allergies. http://allergies.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=allergies&zu=http%3A%2F%2Fwww.foodallergy.org%2Fpress_releases%2Fseafoodpress.html

Terence L.T. LAU, Ph.D. is the chief scientific officer and general manager at HKDNA Chips Limited (Hong Kong). Reach him at [email protected] or (852) 2111-2123.