Nucleic Acid Detection Using Fluorescence Thresholds
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Solution Overview
Problem
Current nucleic acid detection methods, such as PCR and LAMP, face challenges including high costs, need for skilled operators, and issues with false positive signals due to primer-dimer formation, necessitating the development of cost-effective and accurate diagnostic solutions for point-of-care settings, particularly for detecting infectious agents like SARS-CoV-2.
Innovation Solution
A method and device for detecting target nucleic acids in biological samples using fluorescent labeling and isothermal amplification, where the presence or absence is determined by analyzing parameters like baseline fluorescence, time to start of reaction, and peak fluorescence intensity, reducing false positives through specific classification criteria.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If isothermal amplification (LAMP) is used instead of PCR, then cost and operational complexity are reduced, but specificity decreases due to false positive signals from primer-dimer formation
Solution Approach 1:
The patent applies preliminary action by analyzing the baseline fluorescence level before amplification occurs. By establishing a threshold for acceptable baseline fluorescence, the system proactively identifies and eliminates false positive signals before they can lead to incorrect diagnostic results. This preliminary check prevents primer-dimer formation from causing false positives, thereby maintaining high specificity while using the cost-effective LAMP method.
2Measurement precision
If multiple parameters are analyzed for classification, then detection accuracy and specificity are improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the detection process into distinct analytical stages: baseline fluorescence assessment, amplification monitoring, and peak fluorescence analysis. Each stage evaluates a specific parameter independently, and the results are combined for final classification. This segmented approach enables comprehensive multi-parameter analysis while keeping the device architecture modular and manageable, avoiding overwhelming complexity.
3Productivity
If rapid point-of-care detection is implemented, then time to result is reduced, but the need for skilled operators and sophisticated equipment increases
Solution Approach 1:
The patent applies self-service by implementing an automated classification system that independently evaluates multiple parameters (baseline fluorescence, amplification curve, peak fluorescence) and determines the diagnostic result without human intervention. The device autonomously classifies samples as positive, negative, or indeterminate based on pre-programmed criteria, eliminating the need for skilled operators to interpret complex data manually. This enables rapid point-of-care detection while maintaining ease of operation through full automation.
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 method and device provide rapid, accurate, and cost-effective point-of-care detection of nucleic acids, improving specificity and reducing false positives, enabling reliable diagnosis of infections like COVID-19 without the need for extensive processing or skilled operators.
Implementation Method 1
fluorescent labelling of any amplified product; detecting fluorescence
Implementation Method 2
comprises a plurality of circumferential ribs configured to collect a predetermined volume of liquid sample by capillary action and adhesion
Data Source
AI summary
Disclosed herein is a method of detecting a target nucleic acid in a biological sample, the method comprising: i) combining the sample with reagents to enable amplification of the target nucleic acid and fluorescent labelling of any amplified product; ii) detecting fluorescence, and optionally determining that the baseline fluorescence level of the amplification reaction does not exceed a predetermined threshold; and iii) determining whether the target nucleic acid is present in the sample based on one or more of the following parameters: a) time to start of reaction, signalled by an increase in fluorescence; b) peak fluorescence intensity.