Dual-Target RT-LAMP Kit for Rapid SARS-CoV-2 Differentiation

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Solution Overview

Problem

There is a need for rapid, sensitive, and cost-effective diagnostic methods to differentiate between SARS-CoV-2 infection and other highly human-pathogenic Betacoronavirus group B/C infections, such as SARS-CoV and MERS-CoV, particularly in low-resource settings.

Innovation Solution

Development of optimized RT-LAMP primer sets targeting the N gene for SARS-CoV-2 and the RdRp gene for Betacoronavirus group B/C, enabling rapid differential diagnosis with high sensitivity and specificity, including detection of variants of concern.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If RT-LAMP assay is used for rapid detection, then detection speed is improved (within 30 min), but differentiation capability between SARS-CoV-2 and other Betacoronaviruses deteriorates

Engineering Contradiction:
Improvedetection timeVSAvoiddifferential diagnosis capability
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The detection system is segmented into two independent RT-LAMP assays: one targeting the N gene for SARS-CoV-2 detection and another targeting the RdRp gene for Betacoronavirus group B/C detection. Each assay uses specific primers designed to recognize unique genomic regions, allowing simultaneous rapid detection and differentiation of SARS-CoV-2 from other related coronaviruses within 30 minutes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The RdRp gene target serves a dual function: it detects Betacoronavirus group B/C infections and provides a reference for differential diagnosis. By designing the primer set to target a conserved region in the RdRp gene across multiple coronavirus species, the assay achieves broad detection capability while maintaining specificity through the N gene target for SARS-CoV-2 identification.

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

2Loss of time

If RT-LAMP assay is used for rapid detection, then detection speed is improved (within 30 min), but infrastructure requirements worsen (still requires laboratory equipment)

Engineering Contradiction:
Improvedetection timeVSAvoidinfrastructure requirements
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The RT-LAMP assay replaces the complex thermal cycling mechanical system of PCR with an isothermal amplification system that maintains a constant temperature of 65°C. This substitution eliminates the need for sophisticated thermal cyclers, allowing the use of simpler heating devices while maintaining rapid detection capability within 30 minutes and reducing infrastructure complexity.

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

3Measurement precision

If RT-LAMP assay is used, then sensitivity is improved (detects 10 genome copies), but cost worsens (requires optimized primer sets and reagents)

Engineering Contradiction:
Improvedetection sensitivityVSAvoidcost of reagents
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The primer sets are optimized with specific parameters including annealing temperature (65°C), primer concentrations, and Mg2+ concentration to achieve high sensitivity detection of 10 genome copies. By carefully adjusting these parameters during development, the assay achieves superior sensitivity while using standard RT-LAMP reagents that can be manufactured at reasonable costs, balancing performance with ease of manufacture.

Inventive Principle:
Principle #35Parameter 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

The primer sets achieve rapid detection of SARS-CoV-2 with a limit of 10 genome copies per reaction in less than 15 minutes, offering superior sensitivity and specificity compared to existing methods, and allow differentiation from other Betacoronaviruses.

Implementation Method 1

The RT-LAMP assay uses a DNA polymerization enzyme with high strand-displacement activity and 6 primers, specifically designed to recognize 8 distinct regions on the target gene, to synthesize large amounts of target viral nucleic acids under a constant temperature (65°C)

Methodology Applied
Scientific EffectDNA polymerization: Enzyme

Implementation Method 2

The RT-LAMP (reverse-transcription loop-mediated isothermal amplification) appears among the most promising assays

Methodology Applied
Scientific EffectReverse transcription: Enzyme

Implementation Method 3

turbidity, as the reaction produces large amounts of magnesium pyrophosphate (a white precipitate)

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 4

fluorescence, using DNA intercaling dyes

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4176089B1Rapid detection kit for human pathogenic coronaviruses : betacoronavirus group b/c and SARS-cov-2
Publication Date: 2025.09.10 INST PASTEUR
  • EP4176089B1 patent drawingFigure 1
  • EP4176089B1 patent drawingFigure 1
  • EP4176089B1 patent drawingFigure 1

AI summary

The invention relates to reagents and methods for the rapid detection of the presence and/or absence of SARS-CoV-2 or other betacoronavirus group B/C nucleic acid in a sample and their use for the diagnosis of an infection or the detection of an environmental contamination by SARS-CoV-2 or other betacoronavirus group B/C.