Immunochromatographic Test Strip Using Tris Buffer to Suppress Colloidal Gold Aggregation
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Solution Overview
Problem
Immunochromatographic test strips using whole blood as a sample with polybrene as a blood-agglutinating agent and colloidal gold conjugates as detection reagents face the challenge of colloidal gold conjugate aggregation, which cannot be effectively prevented by neutralizing polybrene with polyanions, as seen in previous techniques.
Innovation Solution
Incorporating a Tris buffer solution in the test strip and sample-supply portion to suppress the aggregation of colloidal gold conjugates due to polybrene, eliminating the need for polyanion neutralization, thereby allowing for effective agglutination and separation of red blood cells without conjugate aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polybrene is used as a blood-agglutinating agent to separate red blood cells, then red blood cell separation is improved, but colloidal gold conjugate aggregation occurs
Solution Approach 1:
A polyanion is introduced as an intermediary substance between polybrene and colloidal gold conjugates. The polyanion neutralizes the positive charge of polybrene through electrostatic interaction, preventing polybrene from causing colloidal gold conjugate aggregation while maintaining its red blood cell agglutination function. This mediator approach resolves the contradiction by adding a third component that modulates the interaction between the existing components.
Solution Approach 2:
The polyanion is applied in advance to counteract the harmful effect of polybrene before it can cause colloidal gold conjugate aggregation. By pre-neutralizing the positive charge of polybrene, the system prevents the subsequent aggregation issue while preserving the blood separation function.
2Object-generated harmful factors
If polyanion is added to neutralize polybrene, then colloidal gold conjugate aggregation is reduced, but red blood cell agglutination efficiency decreases
Solution Approach 1:
The concentration ratio between polyanion and polybrene is optimized to achieve the right balance. By carefully controlling the amount of polyanion relative to polybrene, the system neutralizes enough positive charge to prevent colloidal gold aggregation while retaining sufficient positive charge for effective red blood cell agglutination. This parameter optimization resolves the contradiction between reducing aggregation and maintaining agglutination efficiency.
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 enables accurate detection and measurement of analytes in whole blood samples by preventing colloidal gold conjugate aggregation, simplifying the reagent configuration and reducing unpredictable effects on immune reactions and analyte spread.
Implementation Method 1
a buffer solution having an ability to suppress aggregation of the conjugate due to polybrene
Implementation Method 2
An example of a label constituting a detection reagent (conjugate) such as the labeled antibody is colloidal gold particles and a color reaction of the colloidal gold particles enables qualitative detection
Implementation Method 3
the analyte in the sample specifically binds to the labeled antibody to form a complex and the complex spreads through the spreading portion
Implementation Method 4
red blood cells must preliminarily be separated and removed from the whole blood and known methods include a method of removing red blood cells after sedimentation through centrifugation before measurement, and a method of filtrating and removing red blood cells agglutinated by a red blood cell-separating agent
Data Source
AI summary
A problem to be solved by the present invention is to provide an immunochromatographic test strip and a detection method using immunochromatography avoiding aggregation of colloidal gold conjugates while red blood cells in whole blood are agglutinated and then separated and removed in the case of using polybrene as a blood-agglutinating agent and the colloidal gold conjugates as a detection reagent. To solve the problem, the present inventers reviewed a past reagent configuration itself from a completely different viewpoint rather than selecting type and amount of polyanions and, as a result of extensive study on each element, the inventers surprisingly found that aggregation of colloidal gold can be suppressed by using a certain buffer solution without using neutralization by polyanions.