Digital PCR detection system based on visual analysis

Abstract

The utility model relates to a digital PCR (Polymerase Chain Reaction) detection system based on visual analysis, which comprises a turntable coupled on a bracket and a perforation group arranged along the circumferential direction and penetrating through the turntable, the perforation group comprises two mounting holes arranged along the radial direction and positioned on two sides of the axis of the turntable, and a first optical filter and a second optical filter are respectively arranged in the two mounting holes. And the wavelengths of the first optical filter and the second optical filter in different perforated hole groups are matched with the correspondingly detected fluorescent dye. According to the utility model, the plurality of perforation groups are arranged, the plurality of first optical filters and the plurality of second optical filters are arranged, and each perforation group corresponds to one detection channel, so that the detection of various types of fluorescence can be realized, and each detection channel is independently corresponding to prevent the interference of external fluorescence signals; according to the requirements of customers, free matching of different fluorescence detections is realized; and time cross resolution scanning is carried out, that is, when one detection channel is in, other channels are not in the detection range of the camera, so that fluorescence does not interfere with each other when each detection channel runs.

Description

Technical Field

[0001] This invention relates to the field of in vitro diagnostic gene detection technology, and in particular to the detection of target fluorescence through a combination of optics and vision, specifically a digital PCR detection system based on visual analysis. Background Technology

[0002] Digital PCR (dPCR) is an absolute quantification technique for nucleic acid molecules that was developed in the late 1990s. Digital PCR technology can directly count the number of DNA molecules, achieving absolute quantitative analysis of samples. Compared with traditional real-time quantitative PCR (qPCR), digital PCR not only improves the sensitivity and accuracy of detection but also allows for the detection of rare targets in complex backgrounds and exhibits better tolerance to inhibitors.

[0003] Typically, samples are prepared into 20,000 molecular units, each with a diameter of approximately 100 micrometers. With such a large sample volume, current technology faces several challenges: most digital PCR systems can only measure a few types of fluorescence, limiting the ability to simultaneously detect multiple different targets in the same sample; due to the large sample size, traditional individual detection methods are very slow. Furthermore, the wavelength of commercially available LED excitation sources may not perfectly match the center wavelength of the paired filter, resulting in reduced excitation energy and decreased detection sensitivity. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a visual analysis-based digital PCR detection system. It combines multiple fluorescence channels for detection, enabling multiplex fluorescence detection. Each detection channel is an independent entity, and any channel detection module can be freely combined according to the customer's experimental needs, thus achieving multiplex fluorescence detection and improving detection efficiency.

[0005] This utility model is achieved through the following technical solution: a digital PCR detection system based on visual analysis, comprising a light source, a first lens, a first filter, a first collimating lens, and a second lens arranged sequentially on the incident light path; a third lens, a second collimating lens, and a second filter arranged sequentially on the reflected light path; and a camera; further comprising a turntable axially mounted on a bracket, and a perforation group arranged circumferentially and penetrating the turntable, wherein the perforation group includes two mounting holes arranged radially, and the first filter and the second filter are respectively installed in the two mounting holes, and the wavelengths of the first filter and the second filter in different perforation groups are adapted to the corresponding fluorescent dyes to be detected.

[0006] When this utility model is in use, the excitation light source is lit up, and after being scattered by the first lens, it passes through the first filter to filter out other wavelengths of light in the dispersed beam, leaving only the required wavelength. Then, it passes through the first collimating lens to be converted into a parallel beam, and then passes through the second lens to be focused onto the glass slide.

[0007] If there is a fluorescence signal output on the slide, it is collimated into parallel light from a light source point after passing through the third lens, and then focused onto the camera by the second collimating lens. It will pass through the second filter in the middle to filter out other wavelengths of light source signals, leaving only the required wavelength. Finally, the camera is used to take a picture to complete the entire fluorescence detection process.

[0008] Meanwhile, since the wavelengths of the first and second filters in different perforation groups are adapted to the corresponding fluorescent dyes being detected, when different fluorescence detections are required, the turntable is rotated to position the corresponding first filter in the incident light path and the second filter in the reflected light path, thereby enabling the replacement of multiple detection channels and improving detection efficiency. At the same time, each detection channel is independent and corresponding, preventing interference from external fluorescence signals. According to customer needs, different fluorescence detections can be freely combined.

[0009] Preferably, a number of first filters and a number of second filters are located on both sides of a diameter of the turntable.

[0010] This preferred design avoids the first and second filters being arranged in an alternating pattern around the turntable, thus improving efficiency when changing detection channels.

[0011] Preferably, the two mounting holes in the same perforation group are located on opposite sides of the turntable axis.

[0012] The preferred solution adjusts the distance between the first filter and the second filter to avoid mutual interference between the incident light path and the reflected light path.

[0013] Preferably, the first lens is a prism.

[0014] This preferred scheme, through the use of a prism, can increase the excitation energy intensity, ensuring a beam across the 410-660nm range and better matching the center wavelength of the corresponding excitation end filter. White light is received from one side of the prism and emitted from the other. Since the refractive index of the same medium differs for various monochromatic lights, according to the law of refraction, the deflection angles of each monochromatic light will also differ. Therefore, white light passing through the prism will separate the monochromatic lights, forming seven colors: red, orange, yellow, green, blue, indigo, and violet—this is known as dispersion.

[0015] Preferably, the second lens and the third lens are an integrated lens.

[0016] This preferred solution facilitates the simultaneous installation of the second and third lenses by using an integrated mirror. The portion of the integrated mirror located in the incident light path is the second lens, and the portion located in the reflected light path is the third lens.

[0017] Preferably, the integrated lens is a Fresnel lens.

[0018] This preferred solution employs a Fresnel lens, which can focus peripheral light sources onto the lens's central axis, preventing the dissipation of peripheral light and ensuring strong fluorescence energy received by the camera. The principle of a Fresnel lens is to transform spherical and aspherical lenses into thin, planar lenses while achieving the same optical effect. Furthermore, through ultra-precision machining, numerous optical-grade rings are fabricated on the planar surface, each acting as an independent lens. Fresnel lenses represent the optimal way to achieve large-scale, planar, thin, and edge-focused lenses.

[0019] Preferably, the camera used for taking pictures is a CCD camera.

[0020] This preferred solution uses a CCD camera to capture a single image of 20,000 molecular units, significantly improving detection efficiency and eliminating the need to inspect each molecular unit individually. With no time lag between the 20,000 molecular units, the consistency of the results is superior.

[0021] The beneficial effects of this invention are as follows: By setting multiple perforation groups and multiple first and second filters, each perforation group corresponds to a detection channel, enabling the detection of multiple fluorescence types. Each detection channel is independent and corresponding, preventing interference from external fluorescence signals. Different fluorescence detection methods can be freely combined according to customer needs. Time-cross resolution scanning ensures that when one detection channel is active, the other channels are not within the camera's detection range, preventing fluorescence interference between detection channels. The Fresnel lens design improves detection sensitivity. For multi-channel fluorescence detection, simply rotating the turntable and adjusting the detection channels achieves multiple fluorescence detection, improving detection efficiency. The CCD camera imaging principle allows for the simultaneous detection of 20,000 molecular units without time difference, further improving detection efficiency. The center wavelength after prism dispersion is closer to the center wavelength of the corresponding excitation end filter, enhancing excitation energy. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a top-down view of the turntable;

[0024] As shown in the figure:

[0025] 1. Light source, 2. First collimating lens, 3. Second collimating lens, 4. Prism, 5. Motor, 6. Glass slide, 7. Turntable, 8. Fresnel lens, 9. CCD camera, 11. First filter, 12. Second filter. Detailed Implementation

[0026] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0027] See attached document Figure 1 This utility model discloses a digital PCR detection system based on visual analysis, comprising a light source 1, a first lens, a first filter 11, a first collimating lens 2, and a second lens arranged sequentially on the incident light path, a third lens, a second collimating lens 3, a second filter 12, and a camera arranged sequentially on the reflected light path.

[0028] The digital PCR detection system also includes a turntable 7 mounted on a support, and a perforation group arranged circumferentially and penetrating the turntable 7. The perforation group includes two mounting holes arranged radially. The first filter 11 and the second filter 12 are respectively installed in the two mounting holes. The wavelengths of the first filter 11 and the second filter 12 in different perforation groups are adapted to the corresponding fluorescent dyes to be detected.

[0029] The bracket is also equipped with a motor 5 that drives the turntable 7 to rotate.

[0030] Several first filters 11 and several second filters 12 are located on both sides of a diameter of the turntable 7, and two mounting holes in the same perforation group are located on both sides of the axis of the turntable 7.

[0031] The first lens is a prism 4, and the second and third lenses are a single integrated mirror. The integrated mirror is a Fresnel lens 8, and the camera is a CCD camera 9, which is existing technology. The integrated mirror is located between the glass slide 6 and the first collimating lens 2.

[0032] Both the first collimating lens 2 and the second collimating lens 3 are plano-convex lenses, which can convert stray light into parallel light or focus parallel light onto a certain point. When in use, the first collimating lens 2 converts light into a parallel beam, and when in use, the second collimating lens 3 focuses the parallel beam onto the CCD camera 9.

[0033] In this embodiment, there are six perforation groups, each perforation group corresponds to a detection channel, that is, there are six detection channels. The wavelength centers corresponding to the first filter 11 and the second filter in each detection channel are different. At the same time, the customer can select the number of perforation groups according to their needs.

[0034] Detection channel one corresponds to fluorescent dyes such as FAM / SYBR Green, with the center wavelength being: excitation 465 nm and reception 525 nm.

[0035] Detection channel two corresponds to fluorescent dyes such as VIC / HEX / JOE / TET, with the center wavelength being: 525nm for excitation and 564nm for reception.

[0036] Detection channel three corresponds to fluorescent dyes such as TAMRA / Cy3, with the center wavelengths being: 540nm for excitation and 586nm for reception.

[0037] Detection channel four corresponds to fluorescent dyes such as ROX / Texas Red, with the center wavelength being: 571nm for excitation and 612nm for reception.

[0038] Detection channel five corresponds to fluorescent dyes such as Cy5, with the center wavelength being: 635nm for excitation and 685nm for reception.

[0039] Detection channel six corresponds to fluorescent dyes such as Cy5.5, with the center wavelength being: 660nm for excitation and 722nm for reception.

[0040] The excitation wavelength corresponds to the first filter 11, and the reception wavelength corresponds to the second filter 12.

[0041] Since different projects require different filters, we can freely combine filters according to the actual needs of our clients.

[0042] It supports the detection of multiple fluorescence, that is, a maximum of multiple sets of first filters 11 and second filters 12 can be mounted on a single turntable 7.

[0043] Each channel is tested independently, without fluorescence interference, avoiding economic costs caused by insufficient or excessive performance for customers.

[0044] In addition, the instrument's light source 1 uses high-quality LED beads, which are dispersed by the prism 4 to increase the intensity of excitation.

[0045] The method employed is time-cross resolution scanning. That is, when one detection channel is used, the other detection channels are outside the detection range of light source 1 and CCD camera 9, thus eliminating fluorescence interference. The six detection channels can be freely switched by rotating turntable 7.

[0046] The glass slide 6 containing the sample should be within the effective focal length range to prevent the molecular units at the edges from having relatively weak energy intensity; the CCD camera 9 should be within the effective focal length range to prevent the molecular units at the edges from being outside the effective pixel range of the camera.

[0047] See attached document Figure 2 The detection channels are divided into 10-1 to 10-6, where A represents the first filter 11 and B represents the second filter 12. That is, 10-1A is the first filter 11 in the first detection channel and 10-1B is the second filter 12 in the first detection channel.

[0048] In use, the light source 1 is lit, and after passing through the prism 4, the light source 1 changes from white light to stray seven-color light. Then, it passes through the first filter 11, which filters out other wavelengths of light in the scattered beam, leaving only the desired wavelength. Then, it passes through the first collimating lens 2, which converts it into a parallel beam, and then it passes through the Fresnel lens 8 and is focused onto the glass slide 6.

[0049] If there is a fluorescence signal output on the slide 6, it is collimated into parallel light from a light source 1 after passing through the Fresnel lens 8, and then focused onto the CCD camera 9 through the second collimating lens 3. In between, it will pass through the second filter 12 to filter out other wavelengths of the light source 1 signal, leaving only the required wavelength. The CCD camera 9 then takes a picture, completing the entire fluorescence detection process.

[0050] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A digital PCR detection system based on visual analysis, characterized in that: Includes a light source (1) located on the incident light path and arranged in sequence, a first lens, a first filter (11), a first collimating lens (2), a second lens, a third lens located on the reflected light path and arranged in sequence, a second collimating lens (3), a second filter (12), and a camera; It also includes a turntable (7) mounted on a bracket, and a perforation group arranged circumferentially and penetrating the turntable (7). The perforation group includes two mounting holes arranged radially. The first filter (11) and the second filter (12) are respectively installed in the two mounting holes. The wavelengths of the first filter (11) and the second filter (12) in different perforation groups are adapted to the corresponding fluorescent dyes to be detected.

2. The visual analysis-based digital PCR detection system according to claim 1, characterized in that: Several first filters (11) and several second filters (12) are located on both sides of a diameter of the turntable (7).

3. The visual analysis-based digital PCR detection system according to claim 1, characterized in that: The two mounting holes in the same perforation group are located on both sides of the axis of the turntable (7).

4. The visual analysis-based digital PCR detection system according to claim 1, characterized in that: The first lens is a prism (4).

5. The visual analysis-based digital PCR detection system according to claim 1, characterized in that: The second and third lenses are a single integrated lens.

6. The visual analysis-based digital PCR detection system according to claim 5, characterized in that: The integrated lens is a Fresnel lens (8).

7. The visual analysis-based digital PCR detection system according to claim 1, characterized in that: The camera used for taking the picture is a CCD camera (9).

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