Immunochromatographic Test Strip with Additive to Suppress Colloidal Gold Agglutination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Immunochromatography using whole blood as a sample with polybrene as a hemagglutinating agent and colloidal gold conjugates as a detection reagent faces issues with agglutination of colloidal gold conjugates, despite attempts to neutralize polybrene's positive charge with polyanions, leading to incomplete separation of red blood cells and inaccurate analyte detection.
Innovation Solution
Incorporating specific additives such as salts of divalent metals, sulfuric acid, sulfurous acid, carboxylic acid chelators, or polybasic amino acids into the immunochromatographic test strip to suppress agglutination of colloidal gold conjugates by polybrene, eliminating the need for polyanion neutralization, thereby allowing for effective separation of red blood cells and accurate analyte detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polybrene is used as a hemagglutinating agent to separate red blood cells, then red blood cell separation is improved, but colloidal gold conjugates agglutinate causing inaccurate detection
Solution Approach 1:
A polyanion is introduced as an intermediary substance between polybrene and colloidal gold conjugates. The polyanion binds to polybrene through electrostatic interaction, forming a complex that prevents polybrene from agglutinating colloidal gold conjugates while maintaining its ability to agglutinate and separate red blood cells. This mediator resolves the contradiction by selectively blocking harmful interactions while preserving beneficial ones.
Solution Approach 2:
The charge characteristics of the system are modified by adding polyanions that neutralize the positive charge of polybrene. This parameter change (charge neutralization) prevents the electrostatic attraction between polybrene and negatively charged colloidal gold conjugates, thereby preventing agglutination while maintaining red blood cell separation functionality.
2Measurement precision
If polyanions are added to neutralize polybrene's positive charge, then colloidal gold agglutination is reduced, but red blood cell separation becomes incomplete
Solution Approach 1:
Different regions of the test strip are assigned different functions: the sample application area contains polybrene for red blood cell separation, while the detection area contains polyanions to protect colloidal gold conjugates. This spatial differentiation of quality allows each region to optimize its specific function without interfering with the other, resolving the contradiction between separation completeness and colloidal gold stability.
Solution Approach 2:
The polyanion is pre-positioned in the detection area before sample application. When the sample flows through the strip, red blood cells are first agglutinated and separated by polybrene in the application area, then the polyanion is already in place to prevent any subsequent agglutination of colloidal gold conjugates in the detection area. This preliminary positioning ensures both separation completeness and colloidal gold stability.
3Ease of operation
If whole blood is used as sample, then direct testing is simplified, but red blood cells clog membrane pores obstructing sample spreading
Solution Approach 1:
Polybrene is pre-loaded onto the test strip in the sample application area. When whole blood is applied, the polybrene immediately agglutinates red blood cells, forming larger aggregates that are easier to separate and remove. This preliminary agglutination action prevents red blood cells from clogging membrane pores during subsequent spreading, maintaining both operational simplicity and spreading speed.
Solution Approach 2:
The harmful effect of red blood cells (pore clogging) is extracted and addressed separately from the main detection process. By using polybrene to agglutinate and separate red blood cells in a dedicated sample preparation area before the sample reaches the membrane, the detection membrane is protected from clogging while whole blood can still be used as the sample type.
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
The use of these additives prevents agglutination of colloidal gold conjugates, enabling accurate detection and measurement of analytes in whole blood samples by ensuring only red blood cells are agglutinated and separated, simplifying the reagent composition and reducing unpredictable effects on the immunoreaction.
Implementation Method 1
polybrene which is a hemagglutinating agent made of a synthetic water-soluble polymer
Implementation Method 2
an additive for suppressing agglutination of a conjugate due to polybrene
Implementation Method 3
the analyte in the sample specifically binds to the labeled antibody to form a complex
Implementation Method 4
An example of a label constituting a conjugate is colloidal gold particles and a color reaction of the colloidal gold particles enables qualitative detection
Data Source
AI summary
A problem of the present invention is to provide an immunochromatographic test strip avoiding agglutination of colloidal gold while red blood cells in whole blood are agglutinated and then separated and removed in the case of using polybrene as a hemagglutinating agent and the colloidal gold conjugates as a detection reagent, and to provide immunochromatography using the test strip. To solve the problem, the present inventors reviewed the composition of the existing reagent itself from a completely different viewpoint rather than the selection of type or amount of polyanions, and as a result of extensive study on each element, the inventors surprisingly found that agglutination of colloidal gold may be suppressed by using a particular additive without neutralization by polyanions.