Rallabhandi Prasad, Cho Chung Y, Nowatzke William L, Oliver Kerry G, Garber Eric A E
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, Maryland 20740.
Radix BioSolutions, Georgetown, Texas 78626, USA.
J Food Prot. 2020 Jun 1;83(6):1050-1056. doi: 10.4315/JFP-19-531.
The xMAP food allergen detection assay (xMAP FADA) can simultaneously detect 15 analytes (14 food allergens plus gluten) in one analysis. The xMAP FADA typically employs two antibody bead sets per analyte, providing built-in confirmation that is not available with other antibody-based assays. Before an analytical method can be used, its reliability must be assessed when conditions of the assay procedure are altered. This study was conducted to determine the effects on assay performance associated with changes in incubation temperature, amounts of the antibody bead cocktail, and concentrations of detection antibody and β-mercaptoethanol in the reduced-denatured extraction buffer. The analysis of buffered-detergent extracts revealed lower responses at 22°C than at 37°C, but temperature had no effect on the analysis of reduced-denatured extracts. Changes in β-mercaptoethanol and detection antibody concentrations had an effect on the detection of only milk in the reduced-denatured extracts. A slight change in the measured bead count was observed when one-fourth of the bead cocktail was used, and a large decrease in the bead count was noted when one-eighth of the recommended amount was used, but this number (≥25) was still sufficient to provide reliable results. Overall, the xMAP FADA was very robust to changes in the assay procedure, which may inadvertently occur.
xMAP食物过敏原检测分析方法（xMAP FADA）能够在一次分析中同时检测15种分析物（14种食物过敏原加麸质）。xMAP FADA通常针对每种分析物使用两组抗体磁珠，提供了其他基于抗体的检测方法所没有的内置确认功能。在使用一种分析方法之前，必须在改变检测程序条件时评估其可靠性。本研究旨在确定孵育温度、抗体磁珠混合物的量、检测抗体的浓度以及还原变性提取缓冲液中β-巯基乙醇的浓度变化对检测性能的影响。对缓冲洗涤剂提取物的分析显示，在22°C时的响应低于37°C，但温度对还原变性提取物的分析没有影响。β-巯基乙醇和检测抗体浓度的变化仅对还原变性提取物中牛奶的检测有影响。当使用四分之一的磁珠混合物时，观察到测量的磁珠计数有轻微变化，当使用推荐量的八分之一时，磁珠计数大幅下降，但这个数字（≥25）仍足以提供可靠的结果。总体而言，xMAP FADA对检测程序中可能意外发生的变化具有很强的耐受性。
