Human Factor XIII Normalization Control for HIV Immunoassay Variability

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Solution Overview

Problem

Current immunodiagnostics for detecting HIV antigens and antibodies in biological samples face errors due to variations in reagent concentration, instrument processing, and biological matrix effects, leading to inconsistent results and high coefficients of variation, which are unacceptable for critical assays like HIV detection.

Innovation Solution

A normalization factor, such as human Factor XIII, is attached to a solid support and included in the assay to correct for errors introduced by sample processing variations and biological matrix effects, allowing for precise detection of analytes by normalizing the assay results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional immunoassays are performed without normalization controls, then the assay can be completed with standard procedures, but the results exhibit high variability and produce spurious positive or negative classifications

Engineering Contradiction:
Improveassay result consistencyVSAvoidresult classification accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces human Factor XIII (hFXIII) as an intermediary normalization control that mediates the measurement process. hFXIII is added to samples at a known concentration and its measured signal serves as a reference to normalize analyte signals, thereby correcting for variations in sample processing, reagent dispensing, and detector performance across different runs and instruments

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the hFXIII signal measured in each sample is used to calculate a normalization factor that is then applied to adjust the analyte results. This feedback loop ensures that variations detected during the assay process are compensated for in the final results, improving both precision and reliability

Inventive Principle:
Principle #23Feedback

2Reliability

If replicate analysis is performed to improve result reliability, then more measurements are obtained, but the coefficient of variation remains high at 50% or more

Engineering Contradiction:
Improveresult consistencyVSAvoidcoefficient of variation
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The hFXIII normalization control acts as an intermediary reference that is measured simultaneously with analytes in replicate analyses. By normalizing each replicate's analyte signal to its corresponding hFXIII signal, the method eliminates common-source variations, thereby reducing the coefficient of variation across replicates from 50% or more to acceptable levels

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple reagents and processing steps are used to detect HIV antigens and antibodies, then comprehensive detection is achieved, but errors from reagent stability and instrument processing accumulate

Engineering Contradiction:
Improvedetection capabilityVSAvoiderror accumulation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The hFXIII normalization control serves as an intermediary reference that traverses the entire assay process alongside all reagents and processing steps. Since hFXIII is processed identically to analytes through all incubation, washing, and detection steps, it captures the cumulative effect of all sources of variation, enabling correction of error accumulation across the comprehensive detection protocol

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The hFXIII normalization control provides universal correction across multiple functions: it corrects for reagent dispensing variations, incubation timing differences, washing efficiency variations, and detector signal fluctuations. This single normalization control universally addresses all sources of error in the multi-step immunoassay process

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If sample matrix effects are accounted for by analyzing different sample types, then broader applicability is achieved, but biological variations introduce additional errors

Engineering Contradiction:
Improvesample type compatibilityVSAvoidbiological variability
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The hFXIII normalization control acts as an intermediary that is added to each sample type (serum, plasma, etc.) at a known concentration. By measuring hFXIII signal in each sample matrix and using it to normalize analyte signals, the method corrects for biological variability inherent to different sample types while maintaining broad applicability across all matrices

Inventive Principle:
Principle #24Intermediary (Mediator)

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 a normalization factor coupled to a solid support significantly reduces variability in assay results, improving the precision and stability of HIV antigen and antibody detection, thereby enhancing the reliability of HIV diagnostic assays.

Implementation Method 1

The amount of hFXIII in a sample is detected in an immunoassay using antibodies to hFXIII subunits immobilized on solid supports

Methodology Applied
Scientific EffectAntigen-antibody binding:

Data Source

PatentEP3276350B1Human factor xiii as a normalization control for immunoassays
Publication Date: 2020.08.05 BIO RAD LABORATORIES INC
  • EP3276350B1 patent drawingFigure 1
  • EP3276350B1 patent drawingFigure 2
  • EP3276350B1 patent drawingFigure 3

AI summary

The present disclosure provides compositions and methods that are useful for normalizing the amount of signal detected in an assay, such as an immunoassay. The compositions and methods are useful for improving the accuracy of immunoassays, such as immunoassays that detect whether a subject is infected with a retrovirus such as HIV.