Robustness Testing of the xMAP Food Allergen Detection Assay: A Multiplex Assay for the Simultaneous Detection of Food Allergens

2020 ◽  
Vol 83 (6) ◽  
pp. 1050-1056 ◽  
Author(s):  
PRASAD RALLABHANDI ◽  
CHUNG Y. CHO ◽  
WILLIAM L. NOWATZKE ◽  
KERRY G. OLIVER ◽  
ERIC A. E. GARBER
Keyword(s):  
Food Allergen ◽  
Incubation Temperature ◽  
Simultaneous Detection ◽  
Multiplex Assay ◽  
Food Allergens ◽  
Assay Procedure ◽  
Extraction Buffer ◽  
Detection Assay ◽  
Assay Performance ◽  
Allergen Detection

ABSTRACT 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. HIGHLIGHTS

scholarly journals Multi-laboratory validation of the xMAP—Food Allergen Detection Assay: A multiplex, antibody-based assay for the simultaneous detection of food allergens

PLoS ONE ◽  
2020 ◽  
Vol 15 (7) ◽  
pp. e0234899
Author(s):  
Eric A. E. Garber ◽  
Chung Y. Cho ◽  
Prasad Rallabhandi ◽  
William L. Nowatzke ◽  
Kerry G. Oliver ◽  
...  
Keyword(s):  
Food Allergen ◽  
Simultaneous Detection ◽  
Food Allergens ◽  
Detection Assay ◽  
Allergen Detection

Extension of xMAP Food Allergen Detection Assay to Include Sesame

2019 ◽  
Vol 83 (1) ◽  
pp. 129-135 ◽  
Author(s):  
CHUNG Y. CHO ◽  
KATHERINE O. IVENS ◽  
WILLIAM L. NOWATZKE ◽  
JASON ROBOTHAM ◽  
MANSOUR SAMADPOUR ◽  
...  
Keyword(s):  
Food Allergen ◽  
Canola Oil ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Sesame Oil ◽  
High Signal ◽  
North American Population ◽  
Detection Assay ◽  
Allergen Detection ◽  
Limit Of Quantitation

ABSTRACT An estimated 0.1 to 0.2% of the North American population is allergic to sesame, and deaths due to anaphylactic shock have been reported. Detecting and quantifying sesame in various food samples is critical to safeguard the allergic population by ensuring accurate ingredient labeling. Because of the modular nature of the xMAP Food Allergen Detection Assay (FADA), it was possible through method extension to add sesame as a validated additional analyte. Because raw and toasted sesame are both commonly used and the two display significantly different antigenicity, three antibodies, one monoclonal and two polyclonal, were conjugated to bead sets to ensure reliable detection. The modified xMAP FADA successfully detected sesame incurred or spiked in baked muffins, spice mix, canola oil, and in both raw and toasted sesame oils with limit of quantitation values ≤ 1.3 ppm of sesame. Canola oil, sesame oil, toasted sesame oil, and olive oil inhibited sesame detection, as did the detection of sesame incurred in foods containing oil (e.g., hummus). Despite this inhibition, the xMAP FADA was still able to reliably detect sesame at levels throughout the dynamic range of the assay (22 to 750 ng of protein per mL) in all the foods examined. Further, the high signal-to-noise ratio of the lowest calibration standard and preliminary studies conjugating the antibodies at higher concentrations indicate an ability to increase the sensitivity of the assay should the need arise. HIGHLIGHTS

Application of Multiantigen Profiling To Detect Pecan

2018 ◽  
Vol 81 (5) ◽  
pp. 700-704 ◽  
Author(s):  
CHUNG Y. CHO ◽  
CAROLINE PUENTE-LELIEVRE ◽  
GRANT D. JONES ◽  
SARAH R. STADIG ◽  
DEBRA A. TAYLOR ◽  
...  
Keyword(s):  
Dna Analysis ◽  
Current Trend ◽  
Diverse Group ◽  
Food Allergens ◽  
Analytical Challenge ◽  
Primary Methods ◽  
Tree Nuts ◽  
Detection And Identification ◽  
Detection Assay ◽  
Allergen Detection

ABSTRACTA problem often encountered in the detection and identification of undeclared tree nut food allergens is the lack of analytical methods. This problem is accentuated by the current trend, whereby the primary methods used to detect food allergens are antibody-based enzyme-linked immunosorbent assays (ELISAs) and the development of analyte-specific antibodies takes months. The recently developed xMAP food allergen detection assay (xMAP FADA) has the ability to generate multiantigen profiles with tree nuts, thereby providing a potential solution to this problem. The xMAP FADA includes 22 antibodies targeting peanut, soy, and nine tree nuts. The high number of antibodies to a diverse group of tree nuts and legumes and the propensity of tree nuts to cross-react have enabled the development of multiantigen profiling, whereby an analyte reacts with the various antibodies to generate a profile. Recently, a question arose regarding the possible presence of pecan dust at a manufacturer of pecan products that also stored fresh produce. The lack of suitable pecan ELISAs created an analytical challenge that was resolved using multiantigen profiling with the xMAP FADA. Pecan was detected on swab samples by using multiantigen profiling and confirmed by DNA analysis. The use of multiantigen profiling provided an analytical capability beyond what was possible with an analyte-specific analytical method.

scholarly journals Development of a High-Throughput Automated Analyzer Using Biochip Array Technology

2005 ◽  
Vol 51 (7) ◽  
pp. 1165-1176 ◽  
Author(s):  
Stephen P FitzGerald ◽  
John V Lamont ◽  
Robert I McConnell ◽  
El O Benchikh
Keyword(s):  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Simultaneous Detection ◽  
Test Results ◽  
Assay Procedure ◽  
Assay Performance ◽  
Array Technology ◽  
Surface Contact Angle ◽  
Commercial Method ◽  
Processing Techniques

Abstract Background: Use of protein array technology over conventional assay methods has advantages that include simultaneous detection of multiple analytes, reduction in sample and reagent volumes, and high output of test results. The susceptibility of ligands to denaturation, however, has impeded production of a stable, reproducible biochip platform, limiting most array assays to manual or, at most, semiautomated processing techniques. Such limitations may be overcome by novel biochip fabrication procedures. Methods: After selection of a suitable biochip substrate, biochip surfaces were chemically modified and assessed to enable optimization of biochip fabrication procedures for different test panels. The assay procedure was then automated on a dedicated instrument, and assay performance was determined for a panel of cytokine markers. Assay results were then compared with a commercial method for measurement of cytokine markers. Results: Secondary ion mass spectrometry and x-ray photoelectron spectroscopy demonstrated appropriate and reproducible modification of the biochip surface. Contact-angle studies also confirmed generation of hydrophobic surfaces that enabled containment of droplets for fabrication of discrete test regions. Automation of the biochip assays on a dedicated instrument produced excellent cytokine marker performance with intra- and interassay imprecision <10% for most analytes. Comparison studies showed good agreement with other methods (r = 0.95–0.99) for cytokines. Conclusion: Performance data from this automated biochip array analyzer provide evidence that it is now possible to produce stable and reproducible biochips for output of more than 2000 test results per hour.

Cross-reactivity profiles of legumes and tree nuts using the xMAP® multiplex food allergen detection assay

2017 ◽  
Vol 409 (25) ◽  
pp. 5999-6014 ◽  
Author(s):  
Chung Y. Cho ◽  
Carolyn Oles ◽  
William Nowatzke ◽  
Kerry Oliver ◽  
Eric A.E. Garber
Keyword(s):  
Food Allergen ◽  
Cross Reactivity ◽  
Tree Nuts ◽  
Detection Assay ◽  
Allergen Detection

scholarly journals Use of IHF-QD Microscopic Analysis for the Detection of Food Allergenic Components: Peanuts and Wheat Protein

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 239 ◽  
Author(s):  
Ludmila Kalčáková ◽  
Bohuslava Tremlová ◽  
Matej Pospiech ◽  
Martin Hostovský ◽  
Dani Dordević ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Food Allergen ◽  
Microscopic Analysis ◽  
Food Allergens ◽  
Wheat Protein ◽  
Qualitative Detection ◽  
Allergen Detection ◽  
Protein Components ◽  
Secondary Antibodies ◽  
Reliable Analytical Method

The aim of the study was to analytically evaluate quantum dots in immunohistofluorescence (IHF-QD) microscopic imaging as detectors of food allergens—peanut and wheat. The experiment was designed as two in silico experiments or simulations: (a) models of pastry samples were prepared with the addition of allergenic components (peanut and wheat protein components) and without the addition of allergenic components, and (b) positive and negative commercial samples underwent food allergen detection. The samples from both simulations were tested by the ELISA and IHF-QD microscopic methods. The primary antibodies (secondary antibodies to a rabbit Fc fragment with labeled CdSe/ZnS QD) were labelled at 525, 585, and 655 nm emissions. The use of quantum dots (QDs) has expanded to many science areas and they are also finding use in food allergen detection, as shown in the study. The study indicated that differences between the ELISA and IHF-QD microscopic methods were not observable among experimentally produced pastry samples with and without allergenic components, although differences were observed among commercial samples. The important value of the study is certainly the differences found in the application of different QD conjugates (525, 585, and 655). The highest contrast was found in the application of 585 QD conjugates that can serve for the possible quantification of present food allergens—peanuts and wheat. The study clearly emphasized that QD can be used for the qualitative detection of food allergens and can represent a reliable analytical method for food allergen detection in different food matrixes.

Cross-reactivity by botanicals used in dietary supplements and spices using the multiplex xMAP food allergen detection assay (xMAP FADA)

2018 ◽  
Vol 410 (23) ◽  
pp. 5791-5806 ◽  
Author(s):  
Ronnie O. Pedersen ◽  
William L. Nowatzke ◽  
Chung Y. Cho ◽  
Kerry G. Oliver ◽  
Eric A. E. Garber
Keyword(s):  
Dietary Supplements ◽  
Food Allergen ◽  
Cross Reactivity ◽  
Detection Assay ◽  
Allergen Detection
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