FRET-Based Protein Detection Method for Tissue Analysis

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Solution Overview

Problem

Conventional immunohistochemistry techniques face challenges with high background noise and low sensitivity due to non-specific binding of antibodies, which hampers accurate protein detection and quantification in tissue samples.

Innovation Solution

A method utilizing a pair of FRET partners, comprising a fluorescent energy donor and acceptor, specifically binds to proteins of interest, reducing background noise through signal amplification and improved signal-to-noise ratio by using two ligands instead of one, and normalizing the FRET signal with a fluorescent DNA marker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional immunohistochemistry uses a single antibody to detect the protein of interest, then the procedure is simple, but the background noise is high due to non-specific binding

Engineering Contradiction:
Improvesimplicity of procedureVSAvoidbackground noise
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a second antibody as an intermediary that binds to the first antibody-protein complex. This second antibody is labeled with a fluorescent tag and enables signal amplification while reducing non-specific binding background noise through the FRET mechanism, resolving the contradiction between procedural simplicity and background noise reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent combines two antibodies into a single detection system where the first antibody binds to the target protein and the second antibody binds to the first antibody. This merging of detection functions creates a sandwich complex that amplifies the specific signal while minimizing non-specific binding, thereby reducing background noise while maintaining operational feasibility.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If conventional immunohistochemistry uses a single antibody, then the procedure is rapid, but the sensitivity is low due to lack of signal amplification

Engineering Contradiction:
Improvespeed of detectionVSAvoidsensitivity
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent merges two antibodies into a single detection complex where the first antibody provides target specificity and the second antibody provides signal amplification through fluorescent labeling. This combination enables rapid detection while achieving high sensitivity through the amplified fluorescent signal, resolving the contradiction between speed and sensitivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the detection parameter from direct antibody binding to FRET-based fluorescent signal detection. By using energy transfer between the fluorescently labeled second antibody and the detection system, the method achieves signal amplification that enhances sensitivity while maintaining the rapid nature of the assay.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If conventional immunohistochemistry uses blocking buffers to reduce non-specific binding, then background noise is reduced, but the procedure requires several additional steps

Engineering Contradiction:
Improvebackground noiseVSAvoidnumber of steps
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses the second antibody as an intermediary that inherently reduces non-specific binding through the FRET mechanism. This eliminates the need for separate blocking buffer steps, as the dual-antibody FRET system provides both signal amplification and background reduction in a streamlined procedure, resolving the contradiction between background noise reduction and procedural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach significantly enhances the signal-to-noise ratio, allowing for more accurate and reliable detection and quantification of proteins, particularly in cases where conventional methods fail, such as in HER2 protein detection for breast cancer treatment eligibility.

Implementation Method 1

utilizing a pair of FRET partners, comprising a fluorescent energy donor and acceptor

Methodology Applied
Scientific EffectFRET (Förster Resonance Energy Transfer):

Implementation Method 2

normalizing the FRET signal with a fluorescent DNA marker

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP2729808B1Improved method for detecting and/or quantifying an analyte at the surface of a cell
Publication Date: 2017.05.17 CISBIO BIOASSAYS
  • EP2729808B1 patent drawingFigure 1~2
  • EP2729808B1 patent drawingFigure 3
  • EP2729808B1 patent drawingFigure 4

AI summary

The invention relates to a method for quantifying a protein expressed at the surface of a cell or present in a tissue sample, said method comprising the use of two ligands capable of binding specifically to a domain of said protein.