Fluorescence Measurement Device Using Inverted Optical Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical-type thermal cyclers face issues with variations in optical alignment and require custom-made sample chambers, limiting the use of standard micro-centrifuge tubes and necessitating perforations or transparent lids for fluorescence measurement.
Innovation Solution
A device that integrates the excitation light source, sample well, and fluorescence detector in a unitary part, allowing for consistent optical alignment and using standard micro-centrifuge tubes without the need for perforations or transparent lids, with LEDs for excitation and photodiodes for detection, and optional filters to enhance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If excitation light sources and optical fluorescence detectors are disposed above the sample tubes in a hinged lid, then fluorescence measurement can be performed, but the lid must be perforated or partly transparent which adds to device complexity
Solution Approach 1:
Instead of placing the excitation light source and detector above the sample tube (conventional approach), the patent inverts the configuration by placing the excitation light source below the sample well and the detector in the lateral wall of the sample well. This eliminates the need for perforated or transparent lids while achieving the same measurement function.
Solution Approach 2:
The patent changes the spatial dimension of measurement from vertical (top-down through lid) to lateral (side-wall detection). The detector is positioned in the lateral wall of the sample well to capture fluorescence emitted sideways, eliminating the need for optical modifications to the lid structure.
2Ease of operation
If a hinged lid with excitation light sources and detectors is used, then fluorescence measurement is possible, but variations in optical alignment occur due to tolerances of the movable lid
Solution Approach 1:
The patent merges the excitation light source, sample well, and detector into a unitary integrated structure. The excitation light source is positioned below the sample well and the detector in the lateral wall of the same well, creating a fixed geometric relationship that eliminates alignment variations caused by movable lid tolerances.
Solution Approach 2:
The patent creates a standardized, reproducible optical path configuration where each sample well is an identical copy with the excitation source and detector positioned at fixed relative locations. This standardization ensures consistent optical alignment across all sample positions without requiring precision adjustment of movable components.
3Adaptability or versatility
If standard plastic sample tubes are used with top-down optical measurement, then sample evaporation occurs and optical grade materials are required which increases cost
Solution Approach 1:
Instead of measuring fluorescence from the top opening of the sample tube (which exposes the sample to evaporation), the patent inverts the measurement approach by using bottom and lateral wall detection through the well structure. This allows the use of capped standard tubes that prevent evaporation while still enabling optical measurement.
Solution Approach 2:
The patent uses the transparent lateral wall of the sample well as an intermediary medium for light transmission. The excitation light passes through the bottom of the well and the fluorescence is detected through the lateral wall, allowing measurement without requiring the sample tube itself to be optical grade material.
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 robust and consistent fluorescence measurement of nucleic acids in standard micro-centrifuge tubes, minimizing sample evaporation and measurement variations, while allowing for the use of non-optical grade materials, thus reducing costs and improving measurement efficiency.
Implementation Method 1
at least one excitation light source for exciting the fluorescent dye in the test samples and at least one optical fluorescence detector for measuring the fluorescence emitted by the dye upon excitation
Implementation Method 2
with LEDs for excitation
Data Source
AI summary
The invention relates to a device (12; 72) for optically measuring fluorescence of nucleic acids in test samples (14). The device (12; 72) comprises a plurality of sample wells (32) each for receiving an upright sample tube (16) made of a transparent material, having a side wall (20) and a bottom end (22) and containing one of the test samples (14) together with at least one fluorescent dye, at least one excitation light source (24; 74, 76, 78, 80) disposed in the vicinity of each sample well (32) for directing an excitation light beam through the side wall (20) of the sample tube (16) into the test sample (14) for exciting the dye, and an optical fluorescence detector (28) disposed underneath the bottom end (22) of each sample tube (16) for capturing fluorescence emitted from the dye in the test sample (14) upon excitation.