Food allergies affect some 15 million Americans. The only treatment for food allergies is a strict avoidance diet. To help ensure the reliability of food labels, analytical methods are employed; the most common being enzyme-linked immunosorbent assays (ELISAs). However, the commonly employed ELISAs are single analyte-specific and cannot distinguish between false positives due to cross-reactive homologous proteins; making the method of questionable utility for regulatory purposes when analyzing for unknown or multiple food allergens. Also, should the need arise to detect additional analytes, extensive research must be undertaken to develop new ELISAs. To address these and other limitations, a multiplex immunoassay, the xMAP® food allergen detection assay (xMAP FADA), was developed using 30 different antibodies against 14 different food allergens plus gluten. Besides incorporating two antibodies for the detection of most analytes, the xMAP FADA also relies on two different extraction protocols; providing multiple confirmatory end-points. Using the xMAP FADA, the cross-reactivities of 45 botanicals used in dietary supplements and spices commercially sold in the USA were assessed. Only a few displayed cross-reactivities with the antibodies in the xMAP FADA at levels exceeding 0.0001%. The utility of the xMAP FADA was exemplified by its ability to detect and distinguish between betel nut, saw palmetto, and acai which are in the same family as coconut. Other botanicals examined included allspice, amchur, anise seed, black pepper, caraway seed, cardamom, cayenne red pepper, sesame seed, poppy seed, white pepper, and wheat grass. The combination of direct antibody detection, multi-antibody profiling, high sensitivity, and a modular design made it possible for the xMAP FADA to distinguish between homologous antigens, provide multiple levels of built-in confirmatory analysis, and optimize the bead set cocktail to address specific needs.

食物过敏影响约1500万美国人。食物过敏的唯一治疗方法是严格避免饮食。为了帮助确保食品标签的可靠性，采用了分析方法。最常见的是酶联免疫吸附测定（ELISA）。但是，由于交叉反应的同源蛋白，常用的ELISA仅对单个分析物具有特异性，不能区分假阳性。当分析未知或多种食物过敏原时，使该方法的可管理性成为可疑的方法。另外，如果需要检测其他分析物，则必须进行广泛的研究以开发新的ELISA。为了解决这些和其他局限性，可以使用多重免疫测定，食品过敏原xMAP®检测（xMAP FADA），使用针对14种不同食物过敏原和面筋的30种不同抗体开发了这种蛋白。xMAP FADA除了包含两种用于检测大多数分析物的抗体外，还依赖于两种不同的提取方案。提供多个确认端点。使用xMAP FADA，评估了在美国商业出售的膳食补充剂和香料中使用的45种植物药的交叉反应性。xMAP FADA中只有极少数抗体显示出超过0.0001％的交叉反应性。xMAP FADA的实用性以其检测和区分与椰子属于同一家族的槟榔，锯棕榈和巴西莓的能力为例。检查过的其他植物药包括五香粉，阿克苏，茴香籽，黑胡椒，香菜籽，豆蔻，卡宴红辣椒，芝麻籽，罂粟籽，白胡椒，和小麦草。直接抗体检测，多抗体谱分析，高灵敏度和模块化设计的结合，使xMAP FADA可以区分同源抗原，提供多个级别的内置确认分析，并优化微珠组混合物以解决具体需求。