PCR Mastermix Encoding via Fluorescence Ratios

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Solution Overview

Problem

Current PCR assays lack methods to ensure correct mastermix usage, leading to potential user errors and false results due to indistinguishable reactions with different fluorophores and constituents, particularly critical in clinical settings.

Innovation Solution

The method involves using a unique combination of two fluorescent dyes at specific concentration ratios in each mastermix solution to encode the identity of the reagents, allowing for fluorescence ratio-based identification of the mastermix, thereby ensuring correct target nucleic acid amplification and reducing errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple PCR assays with different fluorophores are performed side-by-side using pre-mixed mastermix solutions, then assay throughput and productivity are improved, but the risk of user error increases because reactions become indistinguishable without prior identification

Engineering Contradiction:
Improveassay throughputVSAvoidcorrect mastermix usage
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies color coding by incorporating distinct fluorescent dyes into different mastermix solutions at unique concentration ratios. Each mastermix contains a specific combination of fluorescent dyes (e.g., ROX and Cyanine 5) where the ratio serves as a unique identifier. This allows visual and instrumental differentiation of mastermix types, preventing user errors while maintaining high throughput multiplex PCR assays.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If fluorescent dyes are added to mastermix solutions for identification, then measurement precision of mastermix identity is improved, but device complexity increases due to the need for fluorescence detection and ratio calculation

Engineering Contradiction:
Improvemastermix identification accuracyVSAvoidfluorescence detection system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent leverages the universal fluorescence detection capability already present in real-time PCR instruments to serve dual purposes: both detecting the fluorescent probes for target nucleic acid amplification and identifying the mastermix type through fluorescent dye ratios. This multi-functional use of existing instrumentation avoids adding separate identification devices, thereby minimizing increased complexity while achieving precise mastermix identification.

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

3Reliability

If unique fluorescent dye ratios are used to encode mastermix identity, then reliability of assay results is improved by preventing false positives and negatives, but manufacturing precision requirements increase to ensure consistent dye concentrations

Engineering Contradiction:
Improveassay result accuracyVSAvoidfluorescent dye concentration ratio
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary encoding of mastermix solutions with specific fluorescent dye concentration ratios during the mastermix manufacturing process. By pre-establishing unique identifier ratios (e.g., specific ratios of ROX to Cyanine 5 dyes) in each mastermix batch, the system ensures that even with normal manufacturing variability, the ratios remain distinguishable. This preliminary action creates a built-in verification mechanism that maintains assay reliability without requiring extreme manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

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 enhances data reliability by enabling automated identification of mastermix solutions, ensuring correct target nucleic acid amplification and minimizing false positive or false negative results through unique fluorescence ratios that remain consistent despite pipetting errors.

Implementation Method 1

a first fluorescent dye and a second fluorescent dye present at a predetermined concentration ratio that produces a fluorescence ratio of the first fluorescent dye over the second fluorescent dye that is distinguishable from fluorescence ratios produced from other mastermix solutions

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3083992B1A method for coding of multiple PCR reactions for assay recognition
Publication Date: 2018.01.17 ROCHE DIAGNOSTICS GMBH
  • EP3083992B1 patent drawingFigure 1

AI summary

The present invention provides for methods and compositions that use fluorescent dyes for the identification of reagents and solutions that are used to perform PCR assays.