Microchip capillary electrophoresis (Lab-on-chip®) improves detection of celery (Apium graveolens L.) and sesame (Sesamum indicum L.) in foods

PCR is an usual analytical method applied to the detection of food allergens but sensitivity is a crucial problem in conventional post-PCR detection phase. The multiplex PCR approach often leads to adjunctive loss of sensitivity. The main goal of our study was to improve sensitivity in order to simultaneously detect sesame and celery in foods by mean of an end-point PCR protocol, by replacing conventional agarose gel electrophoresis with a Lab-on-chip® platform (microchip-based capillary electrophoresis). The Lab-on-chip®-based detection allowed to obtain the highest sensitivity in singleplex end-point PCR, for celery and sesame-specific primer pairs, using wheat flour as diluting agent. Moreover, in order to simulate a real system, home-made meat balls and commercial soup were artificially spiked with different percentages of sesame/celery (5% cooked meat balls, w/w and 0.1% soups, w/w), and then analyzed. Limits of detection highlighted in this study using Lab-on-chip® capillary electrophoresis were significantly lower if compared to those obtained with classical agarose gel electrophoresis.