Nucleic Acid Probe Immunoassays for Low-Concentration Analytes
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Solution Overview
Problem
Conventional immunoassay techniques face challenges in detecting low-concentration analytes due to non-specific binding and instability of sandwich complexes, leading to reduced sensitivity and specificity, and often result in complex, labor-intensive protocols.
Innovation Solution
A method involving binding an analyte to a capture reagent and a detection reagent linked to a nucleic acid probe, forming a complex, extending the probe to form an anchoring region, and measuring the bound sequence, utilizing techniques like PCR or rolling circle amplification to enhance signal amplification and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sandwich immunoassay techniques are used, then the assay can detect analytes with good sensitivity and specificity, but the detection limit is insufficient for very low-concentration analytes and the protocol becomes complex and labor-intensive
Solution Approach 1:
The patent introduces a nucleic acid probe as an intermediary component that bridges the capture antibody and detection antibody. This probe can be amplified using PCR or rolling circle amplification, creating a measurable signal that indirectly reports analyte presence. This intermediary approach enables detection of very low-concentration analytes without requiring complex manual操作流程, as the amplification can be performed in vitro.
Solution Approach 2:
The patent replaces the traditional direct antibody-antigen binding measurement with a nucleic acid-based amplification system. Instead of relying solely on the physical presence and binding of detection antibodies, the system uses enzymatic amplification of nucleic acid probes to generate a detectable signal, substituting mechanical/biochemical direct measurement with a amplified molecular biology-based detection system.
2Reliability
If conventional sandwich immunoassay techniques are used, then the assay can be performed with standard reagents, but non-specific binding occurs and sandwich complexes become unstable
Solution Approach 1:
The patent segments the sandwich complex into distinct functional modules: capture antibody, nucleic acid probe, and detection antibody. Each component has a specific function and binding site, reducing non-specific interactions. The nucleic acid probe acts as a spacer that physically separates the antibodies, minimizing their potential for non-specific binding to the same target or to each other, thereby stabilizing the sandwich complex.
Solution Approach 2:
The nucleic acid probe serves as an intermediary that reduces non-specific binding between antibodies. By inserting this additional binding element, the system decreases the probability of direct non-specific interactions between the capture and detection antibodies, while the probe itself can be designed with high specificity to avoid non-specific binding.
3Measurement precision
If multiple binding events and reactions are required to improve sensitivity, then detection capability increases, but any suboptimal event reduces overall assay performance
Solution Approach 1:
The nucleic acid probe acts as a robust intermediary that can undergo controlled amplification. The amplification process (PCR or rolling circle) is highly efficient and can be optimized to proceed to completion, ensuring that even low numbers of initial probe molecules generate sufficient signal. This intermediary approach decouples the sensitivity enhancement from the reliability concerns of multiple antibody binding events, as the amplification chemistry is more controllable and efficient.
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
Improves sensitivity and specificity of immunoassays by stabilizing sandwich complexes and amplifying signals, allowing for accurate detection of low-concentration analytes.
Implementation Method 1
extending the probe to form an extended sequence comprising an anchoring region that binds the anchoring reagent
Implementation Method 2
utilizing techniques like PCR or rolling circle amplification to enhance signal amplification and stability
Implementation Method 3
utilizing techniques like PCR or rolling circle amplification to enhance signal amplification and stability
Implementation Method 4
extending the probe to form an extended sequence comprising an anchoring region that binds the anchoring reagent; binding the extended sequence to the anchoring reagent
Data Source
AI summary
The present invention is directed to methods for improving assay specificity and performance in binding assays.