Multiplex Bead Assay for Carrier Protein Quantification

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Solution Overview

Problem

Current methods for estimating carrier protein concentrations in multivalent polysaccharide protein conjugate vaccines are either inaccurate due to negative interference or laborious and costly, particularly when dealing with multiple proteins, and lack the ability to determine individual protein concentrations.

Innovation Solution

A multiplex bead-based competitive inhibition assay using a suspension array system to measure fluorescence signals, allowing for the rapid and precise estimation of individual carrier protein concentrations in vaccine compositions by employing monoclonal or polyclonal antibodies and fluorophore-labeled secondary antibodies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional methods (Lowry, Bradford, Biuret) are used to estimate carrier protein concentration, then total protein content can be determined, but individual protein concentrations cannot be distinguished and negative interference occurs in multivalent vaccines

Engineering Contradiction:
Improveindividual protein concentration determinationVSAvoidaccuracy of protein estimation
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the measurement process by assigning each carrier protein type to specific microbeads with unique fluorescent properties. This segmentation allows individual proteins (CRM197, TT, DT) to be measured separately through their specific antibody-bead interactions, eliminating cross-interference while enabling precise individual concentration determination

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces type-specific monoclonal antibodies as intermediaries between the carrier proteins and the detection system. Each antibody specifically binds to its target protein (e.g., anti-CRM197 antibody binds only to CRM197), mediating the detection process and preventing negative interference from other proteins in the multivalent vaccine

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If ELISA is used to detect multiple proteins, then individual concentrations can be determined, but the process becomes laborious, time-consuming, and costly

Engineering Contradiction:
Improveindividual protein concentration determinationVSAvoidassay throughput and efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent merges multiple ELISA procedures into a single multiplexed assay. Multiple carrier protein measurements are combined in one reaction well by using differentially fluorescent microbeads, allowing simultaneous detection of CRM197, TT, and DT concentrations in a single experiment rather than requiring separate ELISAs for each protein

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal detection platform using suspension array technology that can simultaneously measure multiple proteins with different fluorescent signals. The system uses universal reagents (fluorophore-labeled secondary antibodies) that work across all protein targets, enabling multi-functionality in a single assay format

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

3Reliability

If multiple carrier proteins are used in multivalent vaccines to reduce immune interference, then immune response is improved, but the complexity of determining individual protein concentrations increases

Engineering Contradiction:
Improveimmune response qualityVSAvoidassay system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses fluorescent color changes as the basis for differentiation. Each microbead population is assigned a unique fluorescent signature (different emission wavelengths or intensities), allowing the detection system to distinguish between antibodies bound to different carrier proteins based on the color/fluorescence characteristics of the beads

Inventive Principle:
Principle #32Color changes

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 method provides reproducible, cost-effective, and rapid determination of individual carrier protein concentrations, reducing reagent costs and turnaround time, while maintaining the workflow similarity to ELISA and enabling simultaneous performance of multiple experiments.

Implementation Method 1

employing monoclonal or polyclonal antibodies and fluorophore-labeled secondary antibodies

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3296741B1Multiplex bead based assay for quantification of multiple types of carrier protein in a multivalent conjugate vaccine composition
Publication Date: 2019.08.21 SERUM INST OF INDIA PTE LTD
  • EP3296741B1 patent drawingFigure 1A~1B
  • EP3296741B1 patent drawingFigure 2A~2B
  • EP3296741B1 patent drawingFigure 2C~3A

AI summary

The present disclosure relates to a bead based competitive inhibition assay for estimation of individual concentration of carrier proteins in a multivalent polysaccharide protein (Ps-Pr) conjugate vaccine composition, wherein said composition comprises of atleast 2 different types of carrier protein. The instant disclosure helps to overcome the limitations of physico-chemical techniques for protein quantification and other immunological assay like ELISA.