Immunochromatographic Test Strip Specimen Detection

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Solution Overview

Problem

Immunochromatographic detection methods struggle to differentiate between samples with and without added specimens, particularly in light-colored specimens like plasma, serum, and urine, leading to incorrect diagnoses due to the control line formation even when only the diluting solution is applied.

Innovation Solution

Incorporating a control component, such as hemoglobin, into the immunochromatographic test strip, which captures a complex with a label and antibodies on an insoluble membrane, allowing for the detection of the presence or absence of the control component to determine if a specimen is present, thereby distinguishing between properly and improperly operated samples.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a light-colored specimen (plasma, serum, or urine) is diluted at a high dilution factor, then the analyte concentration is adjusted to a suitable level for detection, but it becomes difficult to distinguish the diluted sample from the diluting solution itself, leading to failure to detect specimen absence

Engineering Contradiction:
Improveanalyte concentration measurementVSAvoidspecimen presence detection
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces hemoglobin as an intermediary substance that serves as a marker to indicate specimen presence. Hemoglobin is added to the diluting solution at a known concentration, and its detection acts as a mediator to verify whether specimen was properly added. The control component detects hemoglobin levels to distinguish between samples with and without specimen, resolving the inability to detect specimen absence in highly diluted light-colored specimens.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If only the diluting solution is dripped onto the test strip due to failure to add specimen, then the control line still forms and indicates successful reaction, but this leads to incorrect negative results or zero concentration determination

Engineering Contradiction:
Improvetest procedure simplicityVSAvoiddiagnostic accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the control component provides information about specimen presence by detecting hemoglobin. The system compares the detected hemoglobin level against expected levels to determine whether specimen was properly added. This feedback loop prevents incorrect negative results by alerting operators when specimen absence is detected, thereby improving diagnostic accuracy while maintaining procedural simplicity.

Inventive Principle:
Principle #23Feedback

3Reliability

If a control component detecting specimen presence is added to the test strip, then specimen absence can be detected, but the device complexity increases with additional components and detection steps

Engineering Contradiction:
Improvespecimen presence detectionVSAvoidtest strip structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the specimen presence detection function with the existing control component structure. The control component is designed to perform both its traditional function and the additional function of detecting hemoglobin as a specimen presence marker. By combining these functions into a single integrated component rather than adding separate detection systems, the patent reduces the overall device complexity while maintaining reliable specimen presence detection capability.

Inventive Principle:
Principle #5Merging (Combining)

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 effectively reduces false negatives and incorrect concentrations by determining if a specimen is added to the diluting solution, ensuring accurate sample detection and reducing errors caused by the absence of specimens in light-colored samples.

Implementation Method 1

an antibody-immobilized insoluble membrane to a which antibody to the control component and antibody to the analyte are immobilized; detecting on the insoluble membrane the complex of the control component and the antibody to the control component

Methodology Applied
Scientific EffectAntigen-antibody binding:

Implementation Method 2

a label to which antibody to the control component is immobilized; detecting on the insoluble membrane the complex of the control component and the antibody to the control component

Methodology Applied
Scientific EffectSpecific binding:

Data Source

PatentEP2693213B1Detection method using immunochromatography capable of determining sample without addition of specimen as operation-failure sample, and test strip for use in same
Publication Date: 2017.07.26 SEKISUI MEDICAL CO LTD
  • EP2693213B1 patent drawingFigure 1

AI summary

An object of the present invention is to provide an immunochromatographic detection method comprising a step of detecting the failure to add a specimen and an immunochromatographic test strip comprising a means for detecting the failure to add a specimen. The inventers provides an immunochromatographic detection method and an immunochromatographic test strip capable of detecting the failure to add a specimen through a step and a means using an antibody solid-phased on an insoluble membrane for capturing the complex of a component (control component) contained in the specimen other than the analyte and a label to which an antibody to the component is immobilized so as to detect the presence or absence of the control component, in an immunochromatographic detection method of detecting an analyte in a sample acquired by diluting the specimen.