Total Antibody Immunoassay Format for IgG/IgM Interference Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current immunoassay methods for detecting IgG and IgM antibodies suffer from false negatives, false positives, and reduced sensitivity due to non-specific binding and heterophilic antibody interference, particularly in the detection of infectious diseases.
Innovation Solution
A novel immunoassay format combining the principles of the double antigens sandwich method, indirect method, and immunocapture method, using a first reagent with antigens and anti-human IgM antibodies coated on a solid phase support, and a second reagent with labelled antigens and anti-human IgG antibodies, forming sandwich structures with IgG and IgM antibodies in the sample.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the indirect method is used with a secondary antibody labelled with a tracer, then the detection can be performed, but non-specific immunoglobulins will non-specifically bind to the solid phase and be recognized by the secondary antibody, resulting in increased background signal and decreased sensitivity
Solution Approach 1:
The detection system is segmented into two independent detection pathways: one using antigen-coated solid phase with anti-human IgM antibody and tracer, another using antigen-coated solid phase with anti-human IgG antibody and tracer. This segmentation allows specific detection of IgM and IgG antibodies separately, avoiding the non-specific binding problem that affects the traditional indirect method where a single secondary antibody detects all immunoglobulins.
Solution Approach 2:
The patent introduces specific anti-human IgM antibody and anti-human IgG antibody as intermediaries between the pathogen antigen and the tracer. These intermediary antibodies provide specificity by only binding to their corresponding antibody classes (IgM or IgG), preventing non-specific recognition of other immunoglobulins that causes background signal in the traditional indirect method.
2Reliability
If the double antigens sandwich method is used, then the detection can be performed, but the antibody analyte may bind to the antigens on two solid phases or the antigens on two tracers, resulting in false negative detection
Solution Approach 1:
The patent applies local quality by making each solid phase carrier specific to one antibody class: one solid phase is coated with anti-human IgM antibody while the other solid phase is coated with anti-human IgG antibody. This local differentiation ensures that IgM antibodies bind only to the IgM-specific solid phase and IgG antibodies bind only to the IgG-specific solid phase, preventing the false negative problem where antibodies bind to both solid phases in the traditional sandwich method.
3Reliability
If the immunocapture method is used with a secondary antibody, then the detection can be performed, but non-specific binding will occur due to the presence of the secondary antibody, affecting detection results
Solution Approach 1:
The patent extracts and eliminates the problematic secondary antibody from the detection system. Instead of using a secondary antibody that binds to the Fc region of immunoglobulins (which causes non-specific binding), the patent directly uses antigen-antibody-tracer sandwich complexes where the tracer is linked to antigen, not to a secondary antibody. This extraction of the secondary antibody component removes the source of non-specific binding while maintaining detection capability.
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 combined method enhances sensitivity and specificity, effectively detecting IgG and IgM antibodies, overcoming the limitations of single-principle methods, and providing comprehensive infection stage detection.
Implementation Method 1
a first reagent containing at least one antigen and an anti-human IgM antibody, the antigen and the anti-human IgM antibody are coated on a solid phase support, and a second reagent containing at least one labelled antigen and a labelled anti-human IgG antibody, wherein the at least one antigen coated on the solid phase support and the at least one labelled antigen are capable of binding to a same IgG antibody or a same IgM antibody in the sample
Data Source
AI summary
A novel immunoassay format design for determining a total antibody, and a kit accordingly provided for detecting antibodies of a pathogen or pathogens of infectious diseases within a human blood sample are provided. The kit includes: a first reagent containing at least one antigen coated on a solid phase support and an anti-human IgM antibody coated on a solid phase support; and a second reagent containing at least one labelled antigen and a labelled anti-human IgG antibody. At least one antigen of the at least one antigen coated on a solid phase support and at least one antigen of the at least one labelled antigen can bind to the same IgG antibody or the same IgM antibody in the sample. In addition, also provided is a new method for detecting an antibody produced after the infection of a pathogen or pathogens in a sample.