Immunoassay Reagent Sulfite Stability Interference
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Solution Overview
Problem
Current immunoassay methods face challenges in accurately measuring specimens with high concentrations of interference substances and hemoglobin, which can interfere with antigen-antibody reactions, particularly in methods like turbidimetric immunoassay and latex agglutination, leading to inaccurate results.
Innovation Solution
Setting the pH of the immunoassay reagent to 7.4 or less and adding a reducing substance such as ascorbic acid or a thiol compound to the sulfite-based reagent to suppress interference effects and mitigate hemoglobin influence, thereby stabilizing the sulfite and enhancing measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sulfite is used to suppress interference effects from high concentration interference substances, then interference suppression effect is improved, but sulfite concentration decreases over time due to oxidation, reducing long-term effectiveness
Solution Approach 1:
A reducing substance is introduced as an intermediary agent that reacts with oxidized sulfite (sulfate) to regenerate active sulfite. This mediator continuously replenishes the sulfite concentration, maintaining its interference suppression capability over time without requiring frequent reagent replacement or concentration increases.
Solution Approach 2:
The chemical state of the sulfite system is dynamically maintained by changing parameters - specifically, the reducing substance converts sulfate (oxidized form) back to sulfite (active form), thereby maintaining the effective concentration parameter of sulfite throughout the reagent's shelf life and measurement period.
2Stability of the object's composition
If pH is set to 7.0 or less to improve sulfite stability, then sulfite stability is improved, but measurement precision may be affected
Solution Approach 1:
The pH parameter is optimized to a specific range (6.5-7.5) that simultaneously satisfies two requirements: maintaining sulfite stability by limiting oxidation while preserving antigen-antibody reaction efficiency. This precise parameter control resolves the contradiction between stability and measurement precision.
3Stability of the object's composition
If reducing substance is added to maintain sulfite stability, then sulfite stability is improved, but reagent composition complexity increases
Solution Approach 1:
The reducing substance serves multiple functions simultaneously: it regenerates sulfite from sulfate, maintains reducing environment for antigen-antibody reactions, and potentially protects other reagent components from oxidation. This multi-functionality justifies the added compositional element by providing multiple benefits from a single addition.
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 method effectively suppresses interference effects from high concentrations of interference substances and hemoglobin, ensuring precise and reliable immunological measurements over time, even in hemolytic specimens, by maintaining the stability of sulfite and reducing hemoglobin's impact.
Implementation Method 1
since the sulfite is gradually oxidized to a sulfate by dissolved oxygen contained in a measurement reagent or oxygen in the air
Implementation Method 2
adding a reducing substance such as ascorbic acid or a thiol compound to the sulfite-based reagent
Implementation Method 3
latex agglutination immunoassay (LIA)
Data Source
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AI summary
It is an object of the present invention to provide: an immunoassay method, which can sufficiently suppress interference effects caused by an interference substance, such as a heterophile antibody or a rheumatoid factor, for a long period of time, even in a case where a measurement specimen contains the interference substance in a high concentration, and is not affected with hemoglobin; and an immunoassay reagent using the same. Specifically, the present invention relates to an immunoassay reagent comprising a sulfite, wherein the pH of the immunoassay reagent is set at 7.4 or less, and the immunoassay reagent further comprises a reducing substance such as ascorbic acid or a salt thereof or a thiol compound.