Homogeneous Analyte Detection via Nucleic Acid Duplex Amplification
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Solution Overview
Problem
Current clinical assays lack the sensitivity to detect low concentrations of proteins and analytes in biological fluids, particularly proteins like PSA, which are crucial for diagnosing and monitoring diseases, due to limitations in heterogeneous detection methods that lead to non-specific binding and reduced sensitivity.
Innovation Solution
A homogeneous assay using binding pairs composed of specificity molecules coupled to nucleic acids of defined stability, where the nucleic acids form a duplex that can be amplified by PCR, allowing for specific and sensitive detection of analytes without physical separation, reducing background noise and enhancing sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If heterogeneous detection methods (ELISA) are used to detect proteins in biological fluids, then the assay can detect proteins present at concentrations greater than 1 picogram/ml, but the method requires multiple physical separation steps that lead to non-specific binding and lowered sensitivity
Solution Approach 1:
The invention extracts and eliminates the physical separation step from the immunoassay procedure. By using a homogeneous assay format where the antibody-antigen complex remains in solution without requiring solid-phase binding and washing steps, the method removes the source of non-specific binding while maintaining detection capability for low concentration proteins
Solution Approach 2:
The invention changes the fundamental parameter of assay format from heterogeneous (solid-phase) to homogeneous (solution-phase). This parameter change eliminates the need for physical separation steps while enabling detection of proteins at concentrations below 1 picogram/ml through reduced background noise and non-specific binding
2Reliability
If heterogeneous methodology with multiple washing steps is used to separate bound analyte from unbound, then physical separation is achieved, but non-specific binding increases and sensitivity decreases
Solution Approach 1:
The invention removes the washing and separation steps entirely from the assay protocol. By using a homogeneous format where detection occurs in solution without solid-phase attachment, the method achieves analyte separation through specific binding recognition alone, eliminating non-specific binding artifacts introduced by mechanical washing steps
3Adaptability or versatility
If conventional immunoassay technology is used for PSA detection, then proteins present at concentrations of 0-4 ng/ml can be detected, but proteins at femtogram/ml concentrations required for monitoring post-prostatectomy patients cannot be detected
Solution Approach 1:
The invention changes the detection limit parameter by transitioning from heterogeneous to homogeneous assay format. This parameter change reduces background noise and non-specific binding, enabling detection of proteins at femtogram/ml concentrations (1000-fold lower than conventional methods) while maintaining the ability to detect proteins across a broad concentration range from ng/ml to fg/ml
4Ease of operation
If homogeneous immunoassays are used for small molecules, then physical separation steps are avoided, but sensitivity is limited and the method is not suitable for large multiepitopic analytes
Solution Approach 1:
The invention creates a universal homogeneous immunoassay method that works for both small molecules and large multiepitopic analytes. By using solution-phase binding with labeled antibodies that remain in solution, the method achieves simplicity for small molecules while extending applicability to large proteins with multiple epitopes, overcoming the limitation of conventional homogeneous assays
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 method provides a highly sensitive and specific means to detect clinically relevant proteins and analytes, including those at low concentrations, by minimizing non-specific binding and improving detection limits, enabling monitoring of diseases such as prostate cancer.
Implementation Method 1
the first and second nucleic acids form a duplex of defined and limited stability
Implementation Method 2
a binding pair having a first binding member comprising a first specificity molecule coupled to a first nucleic acid, and a second binding member comprising a second specificity molecule coupled to a second nucleic acid
Data Source
AI summary
The present invention provides novel binding pair compositions of defined and limited stability comprising nucleic acid detection markers useful for the homogeneous, sensitive detection of analytes. Also provided are methods for the sensitive homogenous detection of analytes, particularly analytes of clinical relevance. Kits for preparing binding pairs of the invention and for performing the methods of the invention are also provided.