Membrane-Based In-Gel LAMP System for Microbial Detection
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Solution Overview
Problem
Current methods for detecting microbial pathogens in environmental and wastewater samples are labor-intensive, require specialized equipment, and are not suitable for large-scale environmental surveillance due to sensitivity to inhibitors and the need for highly trained personnel, especially in resource-limited settings.
Innovation Solution
The development of a membrane-based, in-gel loop-mediated isothermal amplification (mgLAMP) system that integrates heat incubation, fluorescence illumination, and smartphone image analysis for rapid, absolute quantification of microbial pathogens like SARS-CoV-2, allowing for point-of-use detection without the need for thermal cycling or extensive sample preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If RT-qPCR is used for pathogen detection, then detection sensitivity is improved, but device complexity and operational difficulty increase due to specialized thermocycling instrumentation requirements
Solution Approach 1:
The patent replaces the complex thermocycling mechanical system with an isothermal amplification system that operates at a constant temperature (65°C), eliminating the need for specialized thermocycling instrumentation while maintaining detection sensitivity through the use of LAMP amplification followed by gel electrophoresis separation
Solution Approach 2:
The detection system is segmented into separate functional modules: sample preparation, LAMP amplification, gel electrophoresis separation, and detection. This modular approach allows each component to be optimized independently and enables the use of simpler, more accessible equipment for each step rather than requiring a complex integrated thermocycling system
2Measurement precision
If RT-qPCR is used for pathogen detection, then detection accuracy is improved, but ease of operation deteriorates due to requirement for highly-trained personnel
Solution Approach 1:
The complex thermocycling process requiring trained personnel is replaced with an isothermal LAMP amplification system that operates at a constant temperature, significantly simplifying the operational procedure. The method maintains detection accuracy through specific primer design and gel electrophoresis verification while reducing the skill level required for operation
Solution Approach 2:
The LAMP amplification system is designed to be self-regulating at a constant temperature, with the reaction automatically proceeding without continuous monitoring or adjustment. The gel electrophoresis step provides automatic separation and visualization of amplification products, reducing the need for trained personnel to interpret complex real-time PCR data
3Measurement precision
If RT-qPCR is used for environmental surveillance, then detection capability is improved, but productivity decreases due to labor-intensive procedures and time-consuming sample preparation
Solution Approach 1:
The methodology segments the detection process into parallelizable steps: multiple samples can be prepared simultaneously, LAMP amplification can be conducted in multiple tubes or wells at once, and gel electrophoresis can process multiple samples in a single run. This segmented approach enables higher throughput compared to sequential RT-qPCR processing
Solution Approach 2:
The replacement of thermocycling with isothermal amplification eliminates the time-consuming thermal cycling steps, reducing the overall detection time. The constant temperature operation allows for faster amplification kinetics and shorter run times while maintaining detection capability
4Measurement precision
If RT-qPCR is used for pathogen detection in environmental water, then detection sensitivity is improved, but reliability deteriorates due to sensitivity to inhibitors present in environmental water
Solution Approach 1:
The isothermal LAMP amplification system replaces the thermocycling RT-qPCR system, demonstrating greater robustness to environmental inhibitors. The isothermal conditions and different enzymatic mechanism of LAMP make it less susceptible to inhibition by substances commonly found in environmental water samples, while maintaining detection sensitivity
Solution Approach 2:
The gel electrophoresis step, while adding a procedural step, actually improves reliability by providing a visual verification method that can distinguish true positive signals from false positives caused by inhibitors or non-specific amplification. The separation of DNA fragments by size allows for confirmation of specific amplification products
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
Enables reliable, sensitive, and cost-effective detection of microbial pathogens in environmental waters with a limit of detection as low as 0.96 copy/mL, facilitating large-scale environmental surveillance and reducing the need for specialized equipment and trained personnel.
Implementation Method 1
A downstream filter membrane receives the primary filtered sample and traps one or more of the target microorganism, if present, on a membrane, while passing through the membrane particles present in the primary filtered sample that are smaller than the target microorganism
Implementation Method 2
LAMP reagents and hydrogel components for forming a hydrogel are placed on the membrane to form a loaded slide
Implementation Method 3
a fluorescence illuminator is provided to illuminate the sealed, loaded slide. The slide allows visual detection of the presence or absence of one or more fluorescent amplicons
Implementation Method 4
An incubator is configured to heat the sealed, loaded slide
Data Source
AI summary
Disclosed herein is a membrane-based, in-gel loop-mediated isothermal amplification (LAMP) system, kit and method for detection of a target microorganism in a sample suspected of containing the microorganism. LAMP reagents, a lysing agent and a hydrogel are placed together on a filter membrane loaded with a pre-filtered sample. The hydrogel polymerizes over a short time to immobilize any target DNA/RNA particles on the membrane. The system may include a compact, portable device that integrates heat incubation and fluorescence illumination, and also a cloud-based smartphone image analysis application for quantitative results interpretation. If target DNA/RNA are present in the sample, fluorescent amplicons are produced as a result of LAMP reaction. The target microorganisms are detected by visually detecting the presence or absence of the amplicons. The method may be employed for rapid and inexpensive point-of-use (POU) absolute quantification of SARS-CoV-2 in environmental water or wastewater samples with high sensitivity.