Digital Affinity Linkage Assay for Low-Background Detection
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Solution Overview
Problem
Existing methods for detecting and quantifying biomolecules, such as ELISA and immuno-PCR, suffer from high background noise due to non-specific binding of antibodies, limiting sensitivity and precision.
Innovation Solution
A digital affinity linkage assay method involving a solid support, two labeled affinity agents, and partitioning into small volumes to detect targets by co-localization of labels, reducing background noise and enhancing sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If immuno-PCR is used to increase detection sensitivity, then detection sensitivity is improved, but background signal increases due to non-specific binding of antibodies
Solution Approach 1:
The assay is divided into separate functional components: a solid support with capture antibody, and labeled detection antibodies in solution. This segmentation allows the capture function to be immobilized and washed, separating it from the detection function that carries the label, thereby reducing non-specific binding background while maintaining sensitivity
Solution Approach 2:
The solid support acts as an intermediary that immobilizes the capture antibody, enabling physical separation of bound and unbound components. This intermediary structure allows for washing steps that remove non-specifically bound detection antibodies, reducing background signal while preserving specifically bound complexes
2Ease of manufacture
If ELISA is used for detecting and quantifying biomolecules, then the method is simple and established, but the limit of detection and precision of quantification are insufficient
Solution Approach 1:
The assay replaces traditional ELISA optical detection with a different detection mechanism using labeled antibodies that can be detected with higher sensitivity. The solid support-based capture method combined with labeled detection antibodies enables detection limits below what is achievable with conventional ELISA, while maintaining procedural simplicity
3Object-generated harmful factors
If affinity agents are diluted to reduce non-specific binding, then background noise is reduced, but detection sensitivity decreases
Solution Approach 1:
By segmenting the assay into an immobilized capture component and a solution-phase detection component, the system allows capture antibodies to be held at high effective concentration on the solid support without contributing to solution-phase non-specific binding. This enables maintaining high sensitivity while reducing background noise without requiring dilution of affinity agents
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
Significantly reduces background noise and achieves higher detection sensitivity, allowing for lower target detection limits without diluting affinity agents.
Implementation Method 1
the first affinity agent specifically binds to the target, if present, thereby forming a target bound to the first affinity agent
Implementation Method 2
the second and third affinity agents specifically bind to the target, thereby forming a target-labeled affinity agent complex
Implementation Method 3
separating the target bound to the first affinity agent from unbound material in the sample based on the presence or absence of the solid support
Implementation Method 4
separating the target-labeled affinity agent complex from uncomplexed second and third affinity agents based on the presence or absence of the solid support
Data Source
AI summary
Methods of detecting a target in a sample are provided. Kits for performing the methods described herein are also provided.