Discrete 3D Fluorescence Detection for DNA Analysis
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Solution Overview
Problem
Current DNA analysis systems face detection errors due to spectral and spatial aliasing of fluorescence signals, particularly for low-copy number sequences, which limits the sensitivity and accuracy of microsatellite DNA sequence detection.
Innovation Solution
A system employing discrete three-dimensional fluorescence technology with a high-pressure capillary gel electrophoresis mechanism and a detection mechanism using optical fibers to optimize fluorescence signal detection, including a sampling window unit, detection window unit, and fluorescence signal detection unit with single excitation light sources and dichroic mirrors to prevent aliasing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-color fluorescence signals are detected using a plane array CCD with a single excitation light source, then the detection system can handle multiple wavelengths, but spectral aliasing occurs causing weak fluorescence signals to be buried in the tails of strong signals
Solution Approach 1:
The patent divides the detection system into multiple independent detection channels, each with its own excitation light source and detection optics. This segmentation allows each channel to detect a specific wavelength range without interference from other wavelengths, eliminating spectral aliasing while maintaining multi-wavelength detection capability.
Solution Approach 2:
The patent introduces optical filters as intermediary components between the excitation light sources and the sample, and between the sample and the detector. These filters selectively transmit specific wavelength ranges while blocking others, enabling precise wavelength discrimination and preventing signal aliasing.
2Device complexity
If a single excitation light source penetrates through all capillary tube channels, then the system structure is simplified, but excitation intensity decays stepwise causing spatial misalignment and detection errors
Solution Approach 1:
The patent replaces the single excitation light source with multiple independent excitation light sources, each positioned to illuminate a specific capillary tube or group of tubes. This segmentation eliminates the stepwise intensity decay problem by providing dedicated excitation for each channel, ensuring uniform excitation intensity across all detection positions.
Solution Approach 2:
The patent assigns different excitation light sources to different spatial positions or capillary tubes based on their specific detection requirements. Each local detection channel has optimized excitation conditions tailored to its position, ensuring consistent signal quality across the entire array without the decay issues of a single source.
3Productivity
If fluorescence signals from multiple capillary tubes are detected simultaneously by a plane array CCD, then high-throughput detection is achieved, but spatial aliasing interference occurs between neighboring tubes
Solution Approach 1:
The patent divides the detection system into spatially separated detection channels, with each channel having its own detector or detection region. This segmentation physically isolates the detection paths of neighboring capillary tubes, preventing spatial aliasing interference while maintaining the ability to detect multiple channels simultaneously through parallel processing.
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 significantly enhances the sensitivity of DNA analysis, enabling the detection of extremely low-abundance STR sequence fragments and improving the accuracy of genetic identification and MSI disease diagnosis by increasing the fluorescence acquisition limit by more than one order of magnitude.
Implementation Method 1
The excitation light source may excite a fluorescence signal by irradiating a transparent window of the capillary tube
Implementation Method 2
the fluorescence on each capillary tube may be dispersed into a line spectrum according to the wavelength through a plane grating
Implementation Method 3
separation of DNA molecules using thin-layer polyacrylamide gel electrophoresis driven by high pressure
Data Source
AI summary
Embodiments of the present disclosure provide a system for continuous scanning monitoring and analysis based on a discrete three-dimensional fluorescence technology. The system comprises a high-pressure capillary gel electrophoresis mechanism configured to enable passages of different lengths of STR sequence fragments and nucleic acid gene fragments in an energized state; a sampling window unit configured to assemble a plurality of capillary tubes and a plurality of detection optical fibers shared by an excitation light and excited light; and a detection window unit configured to assemble the plurality of detection optical fibers and a fluorescence signal detection unit. The fluorescence signal detection unit is configured to output a plurality of single excitation light sources and obtain fluorescence signals.