Reaction Processor Optical Head Spacing for Fluorescence Interference
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Solution Overview
Problem
In PCR using a reaction processing vessel with a channel, interference occurs between multiple fluorescence detection devices due to overlapping wavelength ranges of excitation and fluorescence light, leading to noise and reduced sensitivity in measurements.
Innovation Solution
A reaction processor design that includes two optical heads with objective lenses disposed side by side in the longitudinal direction of the channel, where the wavelength range of one fluorescence overlaps with the excitation light range of the other, and a holding member positions them. The distance between the optical axes of the lenses is optimized to minimize interference, and a light absorbing layer is used to further reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple fluorescence detection devices are disposed in an extension direction of the channel to detect fluorescence from the sample, then the ability to detect multiple fluorescent dyes simultaneously is improved, but interference between the detection devices occurs due to overlapping wavelength ranges
Solution Approach 1:
The patent transitions from arranging detection devices in one dimension (extension direction of the channel) to arranging them in a different dimension (side by side in the longitudinal direction of the channel). This spatial reconfiguration allows multiple detection devices to operate simultaneously without wavelength interference, as each device detects fluorescence from a different longitudinal position of the sample
2Measurement precision
If excitation light quantity is increased to improve fluorescence detection sensitivity, then the fluorescence signal strength is improved, but the excitation light appears as large noise in the photodetector
Solution Approach 1:
The patent extracts the harmful excitation light from the detection path by detecting fluorescence from a different longitudinal position of the sample. The photodetector is positioned to receive only fluorescence emitted from the irradiation position, excluding the excitation light that passes through or reflects from other regions of the sample
Solution Approach 2:
The patent introduces the longitudinal position of the sample as an intermediary spatial parameter. By detecting fluorescence from a specific longitudinal position rather than collecting all light from the entire sample path, the system selectively captures fluorescence signals while excluding excitation light noise
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 configuration effectively suppresses interference between fluorescence detection devices, allowing for stable and accurate fluorescence signal detection, thereby improving the measurement accuracy and sensitivity of PCR reactions.
Implementation Method 1
a first objective lens for irradiating a sample in the channel with first excitation light and collecting first fluorescence generated from the sample by irradiation with the first excitation light
Implementation Method 2
A light absorbing layer for absorbing excitation light may be disposed between a bottom of the channel in the substrate and the second main surface
Data Source
AI summary
A reaction processor includes: a reaction processing vessel; a first optical head including a first objective lens OB1 for irradiating a sample with first excitation light and collecting first fluorescence generated from the sample; a second optical head including a second objective lens for irradiating a sample with second excitation light and collecting second fluorescence generated from the sample; and a holding member holding the first optical head and the second optical head. The wavelength range of the first fluorescence and the wavelength range of the second excitation light at least partially overlap with each other. A distance between the optical axis of the first objective lens and the optical axis of the second objective lens satisfies 2·P0+2·P1+4·P2+4·P3<P, P0=L·NA/√(1−NA2), P1=t1·NA/√(n12−NA2), P2=t2·NA/√(1−NA2), and P3=t3·NA/√(n32−NA2).