Abstract:

The USA and the EU have legislated to require labeling of foods containing allergic ingredients. There are eight kinds of main allergic ingredients, including peanut and celery. A real-time fluorescent PCR assay was presented for the quantitative detection of peanut and celery ingredients in foods in the present study. When using the second pair of primer and probe (a total of two pairs were designed) of peanut for PCR amplification, among amplified DNA extracted from 27 samples only peanut produced fluorescent signal. Likewise, when using a pair of prime and probe designed using celery DNA for PCR amplification, only Chinese celery and western celery produced fluorescent signal in 18 samples after real-time PCR amplification. The sensitivity test indicated that 3.6 pg of peanut DNA could be detected, with a quantitative formula: y = －3.092261x + 21.216097 (R2 = 0.993068), where y was Ct, and x was natural logarithm of the DNA concentration (the same below); and 4.0 pg of celery DNA could be detected, with a quantitative formula: y = －4.0957441x + 23.412189 (R2 = 0.997039). The results demonstrate that these pairs of prime and probe have high sensitivity and amplification efficiency and therefore can meet the requirement of trace detection of peanut and celery ingredients in foods.

Key words: peanut, celery, real-time PCR, allergen detection