Single-Pad Lateral Flow Assay for Hemoglobin Interference
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Solution Overview
Problem
Point of care tests require simple, efficient, and cost-effective methods for diagnosing biological specimens in various environments, especially in remote or harsh conditions, where equipment and storage control are limited, and existing lateral flow assays are complex and prone to interference from hemoglobin.
Innovation Solution
A single-pad lateral chromatographic flow assay with a substrate deposited as dry form, pre-treated with a lysing buffer, allowing for capillary flow and separation of hemoglobin from analytes, using tetrazolium salts as indicators to provide clear visual results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple pads are used in lateral flow assay, then separation of sample application and reaction zones is achieved, but device complexity increases
Solution Approach 1:
The patent combines the sample application zone and reaction zone into a single pad structure. The single pad contains both zones with distinct functional regions, eliminating the need for multiple separate pads while maintaining the necessary separation of functions through zonal design within the same substrate.
2Measurement precision
If conventional lateral flow assay is used, then detection of analytes is achieved, but hemoglobin interference occurs
Solution Approach 1:
The patent applies local quality by creating distinct zones within the single pad with different properties. The sample application zone is designed to allow hemoglobin to pass through rapidly, while the reaction zone contains the substrate and reagents for specific analyte detection. This zonal differentiation with locally optimized properties enables hemoglobin to migrate through without interfering with the colorimetric reaction in the reaction zone.
Solution Approach 2:
The patent extracts hemoglobin from the reaction zone by designing the single pad structure where hemoglobin migrates through the sample application zone and is physically separated from the reaction zone. The differential migration rates cause hemoglobin to be removed from the region where the colorimetric reaction occurs, eliminating its interference with analyte detection.
3Ease of operation
If simple testing method is used, then ease of operation is improved, but measurement precision may be compromised
Solution Approach 1:
The patent implements self-service through the single pad structure that automatically performs hemoglobin separation and analyte detection in one integrated system. The differential migration properties of the pad materials and the zonal design enable the system to self-separate hemoglobin from the reaction zone without requiring external intervention or complex operational steps, while maintaining accurate analyte detection through the embedded colorimetric reaction.
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 simplifies the testing process, reduces equipment needs, and provides clear, interference-free visual results for analytes like G6PD and lactate dehydrogenase, suitable for point of care testing in diverse environments with stability and rapid diagnostic capabilities.
Implementation Method 1
allowing for capillary flow and separation of hemoglobin from analytes
Implementation Method 2
the single-pad is pre-treated with a lysing buffer to lyse red-blood cells in a blood sample applied in the sample application zone
Implementation Method 3
wherein the resultant of the reaction of the substrate with the preselected analyte is a precipitate
Implementation Method 4
hemoglobin migrates faster than said resultant
Implementation Method 5
allowing for capillary flow and separation of hemoglobin from analytes
Implementation Method 6
using tetrazolium salts as indicators to provide clear visual results
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
The present invention relates to a strip for an improved lateral flow assay of a biological sample on a single plane and a lateral flow chromatography assay using a test device containing the same. The strip of the present invention consists of a single-pad, which can improve lateral flow assay by providing an easy and simple procedure and clear visual reading. The strip of the present invention is consisted of sample application (sample) zone and reactant-resultant zone where the reaction mixture is deposited (reactant) are all on a same plane. In addition, the present invention provides a chromatographic method wherein hemoglobin is separated from analyte by a differential chromatography on the solid phase. Any interference of detection of the result by hemoglobin is removed by the present invention. The present invention provides advantages including an easy and simple procedure with a quick and clear response.