Reverse Lateral Flow Immunoassay for IgE Detection
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Solution Overview
Problem
Current lateral flow immunoassays for detecting allergen-specific IgE have limitations in sensitivity and specificity, particularly for food allergy diagnosis, leading to high false positives and inadequate detection of IgE-mediated allergies.
Innovation Solution
A reverse lateral flow immunoassay (R-LFIA) platform using gold nanoparticles conjugated with antigens and an anti-IgE antibody on the test strip, enhancing sensitivity and specificity by capturing antigen-specific IgE complexes, allowing for rapid and accurate detection of IgE-mediated diseases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional lateral flow immunoassay is used to detect allergen-specific IgE, then the device structure is simple and easy to manufacture, but the sensitivity and specificity are insufficient leading to high false positives
Solution Approach 1:
The patent inverts the conventional lateral flow immunoassay format by placing antigens on colored nanoparticles instead of on the test strip, and immobilizing anti-IgE antibodies on the test strip instead of using IgE-conjugated particles. This reverse configuration enables direct capture of antigen-IgE complexes, significantly improving detection sensitivity and specificity while maintaining the simplicity of the lateral flow device structure
Solution Approach 2:
The patent changes the physical and chemical parameters of the assay system by using gold nanoparticles with specific sizes (10-100 nm) conjugated with antigens, and optimizing the immobilization conditions of anti-IgE antibodies on the test strip. These parameter changes enhance the binding efficiency and detection sensitivity without complicating the overall device structure
2Measurement precision
If antigen concentration is increased to improve detection sensitivity, then more IgE complexes can be formed, but non-specific binding increases leading to false positives
Solution Approach 1:
The patent uses anti-IgE antibodies immobilized on the test strip as intermediaries to capture antigen-IgE complexes. This intermediary approach allows specific recognition and binding of the complexes while preventing non-specific interactions, thereby maintaining high detection sensitivity without increasing false positives
Solution Approach 2:
The patent concentrates the antigen on the surface of colored nanoparticles, creating a localized high-concentration region that enhances IgE binding efficiency. The anti-IgE antibodies are similarly localized on the test strip at the detection zone, ensuring specific capture occurs only at the intended location, thus avoiding non-specific binding throughout the entire strip
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The R-LFIA demonstrates significantly improved sensitivity, approximately 30-fold higher than conventional methods, enabling reliable diagnosis of peanut and other food allergies, with high specificity and flexibility in sample volume, reducing false positives and improving diagnostic accuracy.
Implementation Method 1
coupling the antigens, to which the IgE are specific for and reactive to, to the colored nanoparticles. The formed antigen specific IgE-antigen-nanoparticle complex is then captured and detected
Implementation Method 2
Bibulous material having immobilized specific binding members capable of reacting with antigens or antibodies; A strip of bibulous material in contact with the sample port material and the lateral flow strip
Implementation Method 3
coupling the antigens, to which the IgE are specific for and reactive to, to the colored nanoparticles. The formed antigen specific IgE-antigen-nanoparticle complex is then captured and detected
Data Source
AI summary
This invention discloses a method and composition for detecting and quantifying the human antigen-specific immunoglobulin E (IgE) by a reverse lateral flow immunoassay. In one embodiment of the invention, the human antigen-specific IgE in in a test sample obtained from bodily fluids including whole blood, dried blood, serum, plasma, saliva, tear, secreting fluid from gastrointestinal tract, respiratory tract and inflammation sites, reacts with nanoparticles-coupled antigens, including allergens, natural environmental antigens, pathogenic antigens, autoantigens, carbohydrate antigens, lipid antigens, synthetic drug antigens and haptens. The formed IgE-antigen-nanoparticle complexes are captured by an anti-human IgE antibody dispensed in the position of the Test line, thus developing a chromatographic color either visualized by naked eye or detectable by a lateral flow reader, and the residual antigen-nanoparticle complex will be captured by anti-antigen specific antibody dispensed in the position of Control line to serve as an assay control. The term of “reverse” specifically indicates that the antigen or antigens are conjugated or coupled to the nanoparticles for this claimed lateral flow immunoassay for human IgE detection and quantification, in conjugation with the capture of the formed antigen specific IgE-antigens-nanoparticles by the immobilized anti-IgE antibody in the Test line position.