S-equol Immunoassay Antigen Specificity for Biological Sample Analysis

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Solution Overview

Problem

Current methods for measuring S-equol in biological samples are not specific and accurate, leading to nonspecific reactions and inefficiencies, particularly when comparing to instrumental analysis like HPLC, which is time-consuming and costly.

Innovation Solution

The use of S-equol as a standard and labeled antigen in immunological methods, combined with a primary antibody with low cross-reactivity to other isoflavones, enhances the specificity and accuracy of S-equol measurement, reducing nonspecific reactions and improving measurement range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If immunoassay methods are used to measure equol, then measurement speed and cost-effectiveness are improved, but measurement precision and specificity deteriorate due to nonspecific reactions

Engineering Contradiction:
Improvemeasurement speedVSAvoidspecificity of S-equol measurement
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by using stereoisomer-specific antigens (S-equol or R-equol) in the immunoassay. The antibody selectively binds to a specific stereoisomer form of equol, creating localized specificity within the measurement system. This allows the immunoassay to distinguish S-equol from R-equol and other isoflavone metabolites, resolving the specificity issue while maintaining the speed and cost advantages of immunoassay methods.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If conventional immunoassay with mixed equol antigens is used, then ease of manufacture is improved, but measurement precision deteriorates due to inability to specifically measure S-equol

Engineering Contradiction:
Improvesimplicity of assay preparationVSAvoidaccuracy of S-equol concentration
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by modifying the chemical structure parameter of the antigen from a mixture of stereoisomers to a single specific stereoisomer (S-equol or R-equol). This parameter change in antigen specificity directly improves the accuracy of S-equol measurement while maintaining relative ease of manufacture through standardized antibody production and assay protocols.

Inventive Principle:
Principle #35Parameter changes

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 allows for accurate and rapid measurement of S-equol concentrations, correlating well with HPLC results, while being more cost-effective and faster, enabling quick determination of equol-producing ability and associated health outcomes.

Implementation Method 1

a primary antibody with low cross-reactivity to other isoflavones

Methodology Applied
Scientific EffectAntigen-antibody binding:

Implementation Method 2

a labeled antigen that competes with equol in a biological sample

Methodology Applied
Scientific EffectCompetitive binding:

Data Source

PatentEP2431740B1Method for measurement of equol in biological sample by immunoassay, kit for the measurement, and method for determination of equol production ability of subject
Publication Date: 2016.01.13 EIKEN KAGAKU
  • EP2431740B1 patent drawingFigure 1
  • EP2431740B1 patent drawingFigure 2
  • EP2431740B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a method for measuring equal in a biological sample by an immunological method, a kit for the measurement, and a method for determining equol-producing ability of a subject. The measurement method of the present invention is characterized in that S-equol is used as at least one antigen selected from the group consisting of a standard antigen used for the preparation of a standard curve and a labeled antigen that competes with equol in a biological sample. The kit of the present invention is characterized in including S-equol as at least one antigen selected from the group consisting of the standard antigen and the labeled antigen. The determination method of the present invention includes steps of measuring equal in a biological sample derived from a subject who has ingested soybean isoflavane by an immunological method using S-equol as at least one antigen selected from the group consisting of the standard antigen and the labeled antigen, and determining an equol-producing ability of the subject based on the measured value of equol obtained in the above step.