Multiplex PCR HLA Genotyping via Fluorescent Melt Curve Analysis

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Solution Overview

Problem

Current HLA genotyping methods, such as SSP-PCR, are labor-intensive, time-consuming, and require multiple PCR reactions, making them inefficient for rapid and automated analysis, which is critical in organ transplantation scenarios where timely HLA typing is essential.

Innovation Solution

A multiplex PCR system using a uniform master PCR mixture and a uniform thermocycling profile, combined with fluorescent melt curve analysis, allows for simultaneous amplification and identification of HLA alleles in a single step, reducing the need for multiple reactions and post-run analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional SSP-PCR method is used for HLA genotyping, then multiple PCR reactions are required to define each allele or allele group, but the process becomes labor-intensive and time-consuming

Engineering Contradiction:
ImproveHLA genotyping accuracyVSAvoidTurn-around time
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent combines multiple separate PCR reactions into a single multiplex PCR reaction that simultaneously amplifies multiple HLA alleles using different primer pairs in one test tube. This merging of reactions eliminates the need for multiple separate amplification steps while maintaining the ability to distinguish between different alleles through their unique melting temperatures

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes differences in melting temperature (Tm) as a distinguishing parameter to differentiate between multiple HLA alleles amplified in the same reaction. By designing primers that produce amplicons with distinct Tm values, the system can resolve and identify multiple alleles simultaneously through melt curve analysis, transforming a time-consuming multi-step process into a single rapid assay

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple PCR reactions are performed to genotype HLA loci, then comprehensive allele identification is achieved, but the complexity and number of steps increase

Engineering Contradiction:
ImproveAllele identification completenessVSAvoidNumber of PCR reactions
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple PCR reactions into a single multiplex reaction that can simultaneously amplify and distinguish multiple HLA alleles. This is achieved by incorporating multiple primer pairs with different melting temperatures into one reaction system, allowing comprehensive allele identification without increasing the number of separate reactions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single multiplex PCR reaction serves multiple functions: it amplifies different HLA alleles, distinguishes between them through melting temperature differences, and provides a basis for automated identification. This multi-functional approach replaces what would traditionally require multiple specialized reactions

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

3Measurement precision

If post-run analysis including gel electrophoresis and data evaluation is performed after SSP-PCR, then accurate HLA typing is achieved, but the time required for analysis increases

Engineering Contradiction:
ImproveHLA typing accuracyVSAvoidPost-run analysis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical gel electrophoresis system with a thermal melt curve analysis system. Instead of separating DNA fragments by size through physical migration in a gel matrix, the system uses thermal melting to separate and identify alleles based on their unique melting temperatures, enabling rapid automated analysis without time-consuming electrophoresis

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the phase transition of DNA melting (double-stranded to single-stranded) as the separation mechanism. By monitoring the melting process through fluorescent dye binding changes, the system can rapidly identify different alleles based on their distinct melting temperatures, eliminating the need for prolonged gel electrophoresis and significantly reducing analysis time

Inventive Principle:
Principle #36Phase transitions

4Measurement precision

If highly trained medical technologists perform HLA typing manually, then accurate results are obtained, but the process cannot be easily automated

Engineering Contradiction:
ImproveHLA typing accuracyVSAvoidManual operation requirement
Core Design Contradiction:
Measurement precisionVSExtent of automation

Solution Approach 1:

The multiplex PCR system with melt curve analysis is designed to be self-interpreting through automated software that analyzes the melt curves and identifies HLA alleles based on their characteristic melting temperatures. The system performs both the amplification and the identification functions, eliminating the need for manual interpretation by highly trained technologists while maintaining accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual manual analysis with automated computational analysis of melt curves. Software algorithms automatically detect, measure, and interpret melting temperature profiles to identify HLA alleles, substituting human expertise with automated digital processing that can be scaled and standardized

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach enables rapid and automated HLA genotyping with fewer steps, improving turn-around time and reducing the complexity of the process, making it suitable for critical applications like organ transplantation.

Implementation Method 1

a fluorescent dye able to selectively bind double stranded DNA

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

amplifying the HLA encoding DNA and control encoding DNA in the reaction vessels using a uniform thermocycling profile

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

determining the HLA type by the DNA melting profile in the solutions

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP1871906B8Genotyping HLA loci
Publication Date: 2012.11.21 LINKAGE BIOSCI

AI summary

This invention provides for an improved method for genotyping HLA loci using PCR.