Optical imaging system and sequencer

Abstract

The invention provides an optical imaging system, and the system comprises an illumination module which is used for transmitting illumination laser; the carrying platform module is used for carrying a sample, and the sample carries a fluorophore; the light guiding module is located on a light path of the illumination laser and used for receiving and guiding the illumination laser to the carrying table module, the illumination laser excites the fluorophore to generate detection fluorescence when irradiating the sample, and the light guiding module is further located on a light path of the detection fluorescence and used for receiving the detection fluorescence; the imaging module is used for receiving the detection fluorescence from the light guiding module and generating a fluorescence image of the sample according to the detection fluorescence, and the fluorescence image is used for acquiring base sequence information of the sample; the illumination module, the light guiding module, the carrying table module and the imaging module are connected to the main body frame, and the main body frame is used for keeping the relative positions of the illumination module, the light guiding module, the carrying table module and the imaging module. The invention further provides a sequencer.

Description

Technical Field

[0001] This application relates to the field of gene sequencing technology, and particularly to an optical imaging system and a sequencer including the optical imaging system. Background Art

[0002] With the rapid development of gene detection technology, traditional sequencers for gene detection include an optical system for collecting fluorescence images. In order to collect accurate fluorescence images, there are high requirements for the stability and precision of the optical path structure of the optical system. Summary of the Invention

[0003] In a first aspect of this application, an optical imaging system is provided, including:

[0004] An illumination module for emitting illumination laser;

[0005] A stage module for carrying a sample, where the sample carries a fluorescent group;

[0006] An optical guiding module located on the optical path of the illumination laser, for receiving and guiding the illumination laser to the stage module. When the illumination laser irradiates the sample, the fluorescent group is excited to generate detection fluorescence. The optical guiding module is also located on the optical path of the detection fluorescence for receiving the detection fluorescence;

[0007] An imaging module for receiving the detection fluorescence from the optical guiding module and generating a fluorescence image of the sample based on the detection fluorescence. The fluorescence image is used to obtain the base sequence information of the sample; and

[0008] A main body frame, to which the illumination module, the optical guiding module, the stage module and the imaging module are connected. The main body frame is used to maintain the relative positions among the illumination module, the optical guiding module, the stage module and the imaging module.

[0009] In a second aspect of this application, a sequencer is provided, including:

[0010] The optical imaging system as described above;

[0011] An image processing system electrically connected to the imaging module, for obtaining the base sequence information of the sample based on the fluorescence image generated by the imaging module.

[0012] For the above optical imaging system and sequencer, by fixing and maintaining the relative positions among the illumination module, the optical guiding module, the stage module and the imaging module through the main body frame, it is beneficial to improve the stability and precision of the optical path structure formed by each functional module in the optical imaging system. Description of the Drawings

[0013] Figure 1 It is a three-dimensional structural schematic diagram of the optical imaging system according to the embodiment of the present application.

[0014] Figure 2 It is Figure 1 a three-dimensional structural schematic diagram of the main body frame in

[0015] Figure 3 It is Figure 2 another three-dimensional structural schematic diagram of the main body frame in

[0016] Figure 4 It is Figure 2 a partial three-dimensional structural schematic diagram of the main body frame in

[0017] Figure 5 It is Figure 2 a three-dimensional structural schematic diagram of the top plate in

[0018] Figure 6 It is Figure 1 a three-dimensional structural schematic diagram of the lighting module in

[0019] Figure 7 It is Figure 6 a sectional structural schematic diagram along line VII-VII in

[0020] Figure 8 It is Figure 1 a three-dimensional structural schematic diagram of the stage module in

[0021] Figure 9 It is Figure 1 a partial three-dimensional structural schematic diagram of the optical imaging system in

[0022] Figure 10 It is Figure 9 a three-dimensional structural schematic diagram of a camera component in

[0023] Figure 11 It is Figure 9 another three-dimensional structural schematic diagram of the camera component in

[0024] Figure 12 It is Figure 9 yet another three-dimensional structural schematic diagram of the camera component in

[0025] Figure 13 It is Figure 9 a three-dimensional structural schematic diagram of a mirror component in

[0026] Figure 14 It is Figure 9 another three-dimensional structural schematic diagram of the mirror component in

[0027] Figure 15 It is Figure 9Schematic diagram of the three-dimensional structure of the middle objective lens assembly.

[0028] Figure 16 is Figure 1 Partial three-dimensional structure schematic diagram of the middle imaging assembly and the light guiding assembly.

[0029] Figure 17 is Figure 9 Partial three-dimensional structure schematic diagram of the middle imaging assembly and the light guiding assembly.

[0030] Figure 18 is Figure 17 Schematic diagram of the three-dimensional structure of the dichroic mirror assembly in the middle.

[0031] Figure 19 is Figure 17 Another three-dimensional structure schematic diagram of the dichroic mirror assembly in the middle.

[0032] Figure 20 is Figure 1 Schematic diagram of the optical path structure of the middle optical imaging system.

[0033] Description of main component symbols

[0034] Optical imaging system 100 Slots 4121, 4131, 4133, 4134

[0035] Main body frame 10 Fixed holes 4122, 4123, 4223, 4224, 4251, 4252

[0037] Bottom plate 11 Camera base 413

[0038] Protrusion 111 Front and rear adjustment parts 414

[0039] Screw hole 112 Screws 4141, 4151, 4161 Side plate 12 Left and right adjustment parts 415

[0040] Hollowed-out area 120 Up and down adjustment parts 416

[0041] Flat part 121 Rotation adjustment parts 417

[0042] Inclined part 122 Boss 4171

[0043] Surface 1221 Mirror assembly 42

[0044] Notch 1222 Mirror 421

[0045] Top plate 13 Mounting base 422

[0046] Surfaces 131, 132 Horizontal mounting plate 4221

[0047] Counterbore 1311 Vertical mounting plate 4222

[0048] Boss 133 Horizontal adjusting member 423

[0049] Sides 134, 135 Vertical adjusting member 424

[0050] Threaded hole 4132 Mounting bracket 425

[0051] Mounting hole 136 Tube lens assembly 43

[0052] Support plate 14 Tube lens 431

[0053] Reinforcing plate 15 Flange 432

[0054] Shock-absorbing assembly 16 Filter assembly 44

[0055] Illumination module 20 Filter holder 442

[0056] Optical fiber 21 Light guiding module 50

[0057] Cylindrical lens 22, 23, 26 Objective lens assembly 51

[0058] Filter 24, 441 Objective lens 511

[0059] Beam splitter prism 25 Mounting base 512

[0060] Diaphragm 27 Adjusting base 513

[0061] Doublet lens 28 Motor 514

[0062] Adjusting assembly 29 Adjusting mechanism 515

[0063] Optical fiber rotation adjusting base 291 Thread pair 5151

[0064] Illumination XY adjusting base 292 Fastening screw 5152

[0065] Shaping cylindrical lens adjusting base 293 Auxiliary adjusting member 516

[0066] Front illumination fixing base 294 Dichroic mirror assembly 52, 53, 54 Rear illumination fixing base 295 Dichroic mirror 521

[0067] Diaphragm and lens adjusting member 296 Lens frame 522

[0068] Optical fiber fixing port 297 mounting bracket 5221

[0069] Stage module 30 connecting portion 5222

[0070] First displacement portion 31 adjustment holes 4231, 5223, 5231, 4241

[0072] Second displacement portion 32 adapter block 523

[0073] Rotation portion 33 positioning holes 524

[0074] Carrying portion 34 focusing module 60

[0075] Imaging module 40 reference support 70

[0076] Imaging channels 401, 402 accommodation space S1

[0077] Camera assembly 41 light-receiving surfaces S2, S3

[0078] Camera 411 camera fixing seat 412

[0079] The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. Specific embodiments

[0080] The present application provides a sequencer. The sequencer includes an optical imaging system and an image processing system. The optical imaging system is used to collect multiple fluorescence images of a nucleic acid sample, and the image processing system is used to perform a preset process on the multiple fluorescence images to obtain the base sequence information of the nucleic acid sample.

[0081] Please refer to Figure 1 , the optical imaging system 100 of this embodiment includes a main body frame 10, an illumination module 20, a stage module 30, an imaging module 40, an optical guiding module 50, and a focusing module 60. The illumination module 20, the stage module 30, the imaging module 40, the optical guiding module 50, and the focusing module 60 are connected to the main body frame 10. The main body frame 10 is used to fix the illumination module 20, the stage module 30, the imaging module 40, the optical guiding module 50, and the focusing module 60, and maintain the relative positional relationship among the illumination module 20, the stage module 30, the imaging module 40, the optical guiding module 50, and the focusing module 60.

[0082] The illumination module 20 is used to emit an illumination laser, and the illumination laser is used to irradiate the nucleic acid sample. The carrier module 30 is used to carry a sequencing chip (not shown). A nucleic acid sample is carried on the surface of the sequencing chip away from the carrier module 30. The nucleic acid sample carries a fluorescent group. When the fluorescent group is irradiated by the illumination laser, it is stimulated to produce detection fluorescence. The imaging module 40 is used to receive the detection fluorescence to generate a fluorescent image of the nucleic acid sample. The light guiding module 50 is located on the optical path of the illumination laser and the detection fluorescence, and is used to guide the illumination laser emitted by the illumination module 20 to the nucleic acid sample, and to guide the detection fluorescence to the imaging module 40. The focusing module 60 is used to detect the focus of the objective lens in the light guiding module 50 in real time to ensure imaging accuracy.

[0083] Different bases (including bases A, T, G, and C) on the nucleic acid sample carry different types of fluorescent groups, and different types of fluorescent groups generate detection fluorescence of different wavelengths when excited by the illumination laser. The imaging module 40 generates different fluorescent images based on the detection fluorescence of different wavelengths in a time-sharing manner. By processing the multiple fluorescent images generated by the imaging module 40, the base sequence information of the nucleic acid sample can be obtained.

[0084] Due to the limited field of view of the illumination laser, it is difficult for the illumination laser to completely cover the surface of the nucleic acid sample. In this embodiment, by controlling the stage module 30 to synchronously drive the displacement of the sequencing chip, different positions on the surface of the nucleic acid sample can be sequentially located within the field of view of the illumination laser. This process can be referred to as the scanning process of the nucleic acid sample by the illumination laser. Through the above scanning process, fluorescent images of all regions of the nucleic acid sample can be obtained (each region has one or more corresponding fluorescent images) to obtain the base sequence information of all regions of the nucleic acid sample.

[0085] Please also read Figures 2 to 4 In this embodiment, the main frame 10 includes a bottom plate 11, two side plates 12, a top plate 13, two support plates 14, a reinforcing plate 15 and a plurality of shock absorbing components 16. The top plate 13 is arranged opposite to the bottom plate 11, and the two side plates 12 are arranged opposite to each other and connected between the top plate 13 and the bottom plate 11; the two support plates 14 are located at the front side of the top plate 13, and the reinforcing plate 15 is located at the opposite rear side of the top plate 13, and the two support plates 14 and the reinforcing plate 15 are connected to the top plate 13 and the side plates 12 to strengthen the connection between the top plate 13 and the side plates 12. The plurality of shock absorbing components 16 are fixedly arranged on the two side plates 12 respectively.

[0086] The bottom plate 11 has a generally rectangular structure and has two convex portions 111 extending toward the top plate 13. Two M6 screw holes 112 are respectively formed on the two convex portions 111. The two side plates 12 are respectively fixedly connected to two opposite sides of the bottom plate 11 through the screw holes 112 on the two convex portions 111, and the two side plates 12 are located on the same surface of the bottom plate 11. The screw holes 112 are used to limit the positions of the bottom plate 11 and the side plates 12 during the transportation of the optical machine, improve the stability of the optical machine during long-distance transportation, and avoid changes in the internal components of the optical machine due to external force factors such as vibration and impact, which may affect the relevant performance of the optical machine.

[0087] The two side plates 12 have substantially the same structure. Each side plate 12 includes a flat portion 121 and an inclined portion 122 connected to each other. The flat portion 121 is connected between the bottom plate 11 and the inclined portion 122. The flat portion 121 is generally perpendicular to the bottom plate 11 as a whole, and the inclined portion 122 is inclined toward the direction of the other side plate 12. Then, the two side plates 12 and the bottom plate 11 form a "U"-shaped frame. The "U"-shaped frame formed by the bottom plate 11 and the side plates 12 allows a receiving space S1 to be reserved inside the frame, and the two inclined portions 122 are inclined toward the receiving space S1. Each side plate 12 has a discontinuous structure and is formed with a plurality of hollowed-out areas 120. On the basis of not reducing the rigidity, the self-weight is reduced, so as to reduce the overall weight of the machine while avoiding the adverse effects of deformation on the performance of the optical machine.

[0088] The top plate 13 is fixedly connected to the sides of the two side plates 12 away from the bottom plate 11. That is, the top plate 13 is fixedly connected to the surfaces 1221 of the inclined portions 122 of the two side plates 12 away from the bottom plate 11. The front part of each inclined portion 122 is hollowed out to form a notch 1222, so that the area of the surface 1221 of each inclined portion 122 is reduced. The top plate 13 is supported on the surfaces 1221 of the two inclined portions 122, and the area of the top plate 13 is adapted to the area of the surface 1221. The reduction of the area of the surface 1221 causes the area of the top plate 13 to be reduced accordingly, which is beneficial to reducing the deformation risk of the top plate 13. At the same time, due to the formation of the notch 1222, the weight of the upper inclined portion 122 is reduced, and the overall center of gravity of the main frame 10 is lowered, which is beneficial to reducing the overall weight of the machine and the overall size of the machine and reducing the occupied space.

[0089] The top plate 13 is a continuous generally rectangular block and is parallel to the bottom plate 11. The top plate 13 has a surface 131 fixedly connected to the inclined portion 122 and a surface 132 opposite to and parallel to the surface 131.

[0090] The surface 131 is as Figure 5The honeycomb structure shown is used to reduce the transmission of external vibrations and the rigid deformation, thereby avoiding the adverse effects of vibrations and deformations caused by the movement of the external environment or the platform on the optomechanical performance. Ten countersunk holes 1311 of M6 are also formed on the surface 131 for fixing the top plate 13 to the surface 1221 of the inclined portion 122.

[0091] Four spaced bosses 133 are formed on the surface 132. Each boss 133 is used to accurately install and position the functional modules in the optical imaging system 100. Each boss 133 protrudes relative to the surface 132 and has high-precision requirements for flatness and parallelism, so as to ensure the installation reference of each functional module. Since the area of the boss 133 is relatively smaller than the area of the surface 132, it is easier to ensure high flatness and high parallelism in the manufacturing process. This is beneficial to make the optical path in the optical imaging system 100 accurate to obtain a more precise fluorescence image. In this embodiment, the four bosses 133 are respectively used to install and position the imaging module 40 and the light guiding module 50. Fixing holes and adjusting holes are also provided on the surface 132 of the top plate 13. The fixing holes are used to fix the corresponding functional modules, and the adjusting holes are reserved for adjusting the position and angle of the corresponding functional modules.

[0092] The top plate 13 also has side surfaces 134 and 135 respectively connecting the surface 131 and the surface 132. The side surface 134 and the side surface 135 are parallel and oppositely arranged. One end of each support plate 14 is fixedly connected to the side surface 134, and the other end is fixedly connected to one of the inclined portions 122. The reinforcing plate 15 is substantially parallel to the side surface 135, and the reinforcing plate 15 is fixedly connected to the side surface 135 and the two inclined portions 122 respectively. Through the support plate 14 and the reinforcing plate 15, the fixing strength between the top plate 13 and the two side plates 12 can be further improved.

[0093] In this embodiment, the number of the shock absorption components 16 is four. The four shock absorption components 16 have basically the same structure and function, and the installation positions are horizontal with the center of gravity of the whole optical imaging system 100. In this embodiment, each shock absorption component 16 includes a shock absorption pad and a support member. The shock absorption components 16 are installed on the side plates 12. Specifically, each shock absorption component 16 is installed on the top wall of a hollow area 120 facing the bottom plate 11. The external support structure (not shown in the figure) is connected to the optical imaging system 100 through the shock absorption pad, so as to support the optical imaging system 100 from the side plates 12. The four shock absorption components 16 as a whole can support a weight of more than 80 kg and can isolate vibration frequencies above 20 HZ. In other embodiments, the number and installation positions of the shock absorption components 16 are not limited, as long as they can support the optical imaging system 100 and achieve the shock absorption effect.

[0094] Please refer to Figure 6 and Figure 7, in this embodiment, the lighting module 20 is fixedly arranged on the surface 132 of the top plate 13. The lighting module 20 includes an optical fiber 21, cylindrical lenses 22 and 23, a filter 24, a beam splitter prism 25, a cylindrical lens 26, a diaphragm 27, a doublet lens 28 and an adjustment assembly 29 which are arranged in sequence on the lighting laser optical path. The adjustment assembly 29 is formed with a receiving space for fixing and accommodating the cylindrical lenses 22 and 23, the filter 24, the beam splitter prism 25, the cylindrical lens 26, the diaphragm 27 and the doublet lens 28, and one end of the optical fiber 21 is fixed to the adjustment assembly 29.

[0095] The adjustment assembly 29 includes an optical fiber rotation adjustment base 291, a lighting XY adjustment base 292, a shaping cylindrical lens adjustment base 293, a front lighting fixing base 294, a rear lighting fixing base 295, and a diaphragm and lens adjustment member 296. The optical fiber rotation adjustment base 291 is formed with an optical fiber fixing port 297. The lighting XY adjustment base 292, the shaping cylindrical lens adjustment base 293, the front lighting fixing base 294, the rear lighting fixing base 295, and the diaphragm and lens adjustment member 296 together form a receiving space 298, and the cylindrical lenses 22 and 23, the filter 24, the beam splitter prism 25, the cylindrical lens 26, the diaphragm 27, and the doublet lens 28 are located in the receiving space 298.

[0096] The optical fiber 21 is connected to the optical fiber fixing port 297 and fixed to the optical fiber rotation adjustment base 291 by three pressing screws. The lighting XY adjustment base 292 can adjust the translation of the optical fiber 21 in two mutually perpendicular directions in the plane perpendicular to the lighting laser optical axis through precision adjustment screws and fixing screws. The shaping cylindrical lens adjustment base 293 can adjust the relative rotation position between the cylindrical lenses 22 and 23 to ensure that the two cylindrical lenses are orthogonal. The lighting XY adjustment base 292 and the shaping cylindrical lens adjustment base 293 are adjustable in the direction parallel to the lighting laser optical axis for spot shaping. The optical fiber rotation adjustment base 291, the lighting XY adjustment base 292, and the shaping cylindrical lens adjustment base 293 are fixedly arranged on the front lighting fixing base 294, and the front lighting fixing base 294 and the rear lighting fixing base 295 are relatively adjustable for controlling the spot position of the incident lighting laser. The diaphragm and lens adjustment member 296 is used to adjust the diaphragm 27 and the doublet lens 28 to control the spot shape and uniformity when the lighting laser irradiates the nucleic acid sample.

[0097] The optical fiber 21 serves as the illumination laser emission end and is used to emit two stable and continuous illumination lasers with wavelengths of W1 nm (green laser) and W2 nm (red laser). The cylindrical lenses 22 and 23 serve as shaping components and are used to shape the illumination laser from the optical fiber 21 with a circular spot having a Gaussian brightness distribution into a rectangular spot for emission. The filter 24 has a high cut-off depth for spectra other than W2 nm and W1 nm and is used to filter out light with wavelengths other than W2 nm and W1 nm. The beam splitting prism 25 is used to split the illumination lasers of W2 nm and W1 nm so that they are emitted along different optical paths and the spots are separated on the nucleic acid sample. The illumination lasers emitted by the beam splitting prism 25 pass through the cylindrical lens 26, the aperture 27, and the doublet lens 28 in sequence and are then guided by the light guiding module 50 to the nucleic acid sample, forming red and green linear illumination spots with a certain distance on the surface of the nucleic acid sample, exciting the fluorescent groups on the bases of the nucleic acid sample, and generating detection fluorescence with different wavelengths.

[0098] Please refer to Figure 1 and Figure 8 In this embodiment, the stage module 30 is fixedly arranged on the surface of the bottom plate 11 where the side plate 12 is fixed and is located in the accommodation space S1. The stage module 30 is used to carry the sequencing chip and can be displaced in three directions, thereby driving the sequencing chip to displace synchronously, so that the illumination laser can irradiate different positions on the sequencing chip, and thus irradiate different positions of the sample.

[0099] In this embodiment, the stage module 30 can carry two sequencing chips simultaneously.

[0100] The stage module 30 includes a first displacement part 31, a second displacement part 32, a rotation part 33, and two carrying parts 34 stacked in sequence, where the first displacement part 31 is farthest from the sequencing chip, and the surfaces of the two carrying parts 34 away from the first displacement part 31 can be respectively used to carry a sequencing chip. The first displacement part 31 is used to drive the sequencing chip to linearly displace in the first direction in the plane of the bottom plate 11 synchronously. In this embodiment, the second displacement part 32 is used to drive the sequencing chip to displace in the second direction in the plane of the bottom plate 11, where the first direction is perpendicular to the second direction. The rotation part 33 is used to drive the sequencing chip to rotate in the plane of the bottom plate 11 synchronously. The first displacement part 31 and the second displacement part 32 have a sub-micron positioning accuracy and cooperate with the exposure process of the imaging module 40 to drive the sequencing chip to translate, so that the illumination laser scans the nucleic acid sample on the sequencing chip. The rotation part 33 drives the sequencing chip to rotate a small angle, which is used to finely adjust the placement angle of the sequencing chip so that the direction of the translation of the sequencing chip is accurate.

[0101] In this embodiment, the first displacement part 31 has a sub-micron positioning accuracy, which is beneficial to precisely cooperate with the imaging module to ensure the imaging quality. By using a long guide rail, the first displacement part 31 or the second displacement part 32 can synchronously drive the sequencing chip to move inside and outside the accommodation space S1, facilitating the user to directly pick up and place the sequencing chip. The second displacement part 32 realizes the switching of the two carrying parts 34 to meet the dual-sequencing chip scanning requirements. The rotating part 33 has a load of 3 kg and can achieve precise positioning under the pulling of various pipelines while ensuring that the 500 g carrying part 34 is in place. The two carrying parts 34 can respectively load sequencing chips with different throughputs and can be independently leveled.

[0102] Please refer to Figure 9 , in this embodiment, the imaging module 40 includes two independent imaging channels 401 and 402, and the imaging channel 401 and the imaging channel 402 have basically the same structure and function. The imaging channel 401 and the imaging channel 402 both include a camera assembly 41, a mirror assembly 42, a tube lens assembly 43, and a filter assembly 44. The filter assembly 44 is used to receive the detection fluorescence from the light guiding module 50 and select and transmit the detection fluorescence of a preset wavelength to the tube lens assembly 43. The detection fluorescence of the preset wavelength is successively guided to the camera assembly 41 through the tube lens assembly 43 and the mirror assembly 42. The camera assembly 41 includes a camera 411. In this embodiment, the camera 411 is a Time Delay Integration (TDI) camera, that is, a line array camera. The photosensitive surface of the camera 411 is used to sense the detection fluorescence and outputs corresponding electrical signals according to the sensed detection fluorescence to generate a fluorescence image. The cameras 411 in the two imaging channels are used to receive detection fluorescence of different wavelengths to generate fluorescence images.

[0103] Please refer to Figures 9 to 12 together, the camera assembly 41 further includes a camera fixing seat 412, a camera base 413, a front-back adjusting member 414, a left-right adjusting member 415, an up-down adjusting member 416, and a rotation adjusting member 417.

[0104] The camera fixing seat 412 is fixedly connected to the boss 133 of the top plate 13. Two grooved pin holes are provided on the camera fixing seat 412, and the positioning pin provided on the top plate 13 can be used to determine the approximate position of the imaging focal plane of the camera 411 in the optical axis direction. In this embodiment, the camera fixing seat 412 is a roughly rectangular block, and long slotted holes 4121 perpendicular to the optical axis direction are respectively provided at the four corner positions of the camera fixing seat 412. The entire camera assembly 41 can be fixed on the boss 133 of the top plate 13 by screwing through the slotted holes 4121.

[0105] A fixing hole 4122 is formed on an edge of the camera fixing base 412 parallel to the optical axis. The left - right adjusting member 415 is connected to the camera fixing base 412 through the fixing hole 4122. The left - right adjusting member 415 includes a screw rod 4151. By slightly rotating the screw rod 4151, the camera fixing base 412 can be precisely pushed to displace in a direction perpendicular to the optical axis and parallel to the top plate 13 until the central pixel of the camera 411 in the displacement direction coincides with the optical axis.

[0106] Two fixing holes 4123 are formed on an edge of the camera fixing base 412 perpendicular to the optical axis. The front - back adjusting member 414 is fixed to the camera fixing base 412 through the fixing holes 4123. The camera base 413 is connected to the surface of the camera fixing base 412 away from the top plate 13. The front - back adjusting member 414 includes a screw rod 4141, and the screw rod 4141 is buckled on the camera base 413. By slightly rotating the fine - tuning screw rod 4141, the camera base 413 can be pushed to drive the camera 411 to move back and forth on the camera fixing base 412 along a direction parallel to the optical axis and parallel to the top plate 13, so as to adjust the focal plane position of the camera 411.

[0107] The camera base 413 is integrally in a "T" - shaped structure and is fixedly connected to the surface of the camera fixing base 412 away from the top plate 13. In this embodiment, the surface of the camera base 413 directly contacting the camera fixing base 412 is approximately rectangular, and long slot holes 4131 along the optical axis direction are respectively arranged at its four corners. The slot holes 4131 cooperate with the positioning pins on the camera fixing base 412 to provide guidance for the fine adjustment of the camera 411 in the direction parallel to the optical axis.

[0108] A threaded hole 4132 is formed at the top end of the camera base 413 away from the top plate 13. The up - down adjusting member 416 includes a screw rod 4161, and the screw rod 4161 is connected to the threaded hole 4132. Four long slot holes 4133 are also formed on the camera base 413. Cooperating with the up - down adjusting member 416, by slightly rotating the screw rod 4161, the camera 411 can be driven to displace in a direction perpendicular to the optical axis and the top plate 13, which is convenient for the central pixel of the camera 411 in the displacement direction to be aligned with the optical axis.

[0109] The rotation adjusting member 417 is integrally a frame structure with a central opening, and the central opening corresponds to the photosensitive surface of the camera 411. A boss 4171 is formed at the top end of the rotation adjusting member 417 away from the camera fixing base 412. A slot - type hole and a threaded hole are formed on the boss 4171. Cooperating with the precision adjusting screw and the setscrew, the precise rotation adjustment of the camera 411 in a plane perpendicular to the optical axis can be realized. Four arc - shaped slot holes 4134 are also formed on the camera base 413. Cooperating with the rotation adjusting member 417, they are used to fix the angular position of the camera 411 after the rotation adjustment of the camera 411.

[0110] The front-back adjustment member 414, the left-right adjustment member 415, the up-down adjustment member 416, and the rotation adjustment member 417 respectively fine-tune the position and angle of the camera 411 in different dimensions, which is beneficial to improving the consistency of multiple indexes such as the imaging quality of the cameras in the two imaging channels and the performance of the optical system.

[0111] Please also refer to Figure 9 , Figure 13 and Figure 14 , the mirror assembly 42 includes a mirror 421, a mounting base 422, a horizontal adjustment member 423, a vertical adjustment member 424, and a fixing bracket 425. The mounting base 422 has a horizontal mounting plate 4221 and a vertical mounting plate 4222 fixedly connected to the horizontal mounting plate 4221. The horizontal mounting plate 4221 and the horizontal adjustment member 423 are connected to the surface of one of the bosses 133 on the top plate 13. The extending direction of the vertical mounting plate 4222 is perpendicular to the horizontal mounting plate 4221. The vertical adjustment member 424 and the fixing bracket 425 are connected to the vertical mounting plate 4222. The fixing bracket 425 is an overall rectangular frame structure, and the mirror 421 is fixed within the frame structure of the fixing bracket 425. In this embodiment, there is a gap between the mirror 421 and the fixing bracket 425, which is beneficial to reducing the stress on the mirror 421 and improving the imaging quality. Glue is injected on the surface of the mirror 421 parallel to the light-receiving surface S2 (the surface for receiving and reflecting the detected fluorescence) to fix the mirror 421 to the fixing bracket 425, preventing the lateral stress (the stress parallel to the light-receiving surface S2 of the mirror) from deforming the mirror 421 and causing the imaging quality to decline. When the mirror 421 is installed on the fixing bracket 425, it is perpendicular to the top plate 13.

[0112] The horizontal mounting plate 4221 is also formed with fixing holes 4223. By inserting a pin into the fixing holes 4223, the entire mirror assembly 42 can be positioned at the corresponding position on the boss 133. The horizontal adjustment member 423 is provided with two adjustment holes 4231 respectively located on both sides of the fixing holes 4223, and the extending direction of the adjustment holes 4231 is perpendicular to the extending direction of the fixing holes 4223. By inserting a set screw into the adjustment holes 4231, the horizontal mounting plate 4221 can be pushed to rotate and fine-tune around the axis of the pin in the fixing holes 4223. When the horizontal mounting plate 4221 rotates, it drives the vertical mounting plate 4222, the fixing bracket 425, and the mirror 421 to rotate synchronously. The horizontal mounting plate 4221 is also formed with two fixing holes 4224. When the mirror 421 rotates to the preset angular position, the mirror 421 can be locked in the rotation direction through bolts and the fixing holes 4224.

[0113] The fixing bracket 425 is formed with fixing holes 4251. By inserting a pin into the fixing holes 4251, the fixing bracket 425 and the mirror 421 can be integrally positioned at corresponding positions on the vertical mounting plate 4222. Two adjusting holes 4241 are provided on the vertical adjusting member 424, which are respectively located on both sides of the fixing hole 4251. The extending direction of the adjusting holes 4241 is perpendicular to the plane where the mirror 421 is located. By inserting set screws into the two adjusting holes 4241, the fixing bracket 425 can be pushed to rotate and finely adjust around the axis of the pin in the fixing hole 4251. When the fixing bracket 425 rotates, the mirror 421 is driven to rotate synchronously. Two fixing holes 4252 are also formed on the fixing bracket 425. When the mirror 421 rotates to a preset angular position, the fixing bracket 425 and the mirror 421 can be locked in the rotational direction through bolts and the fixing holes 4252.

[0114] The mirror 421 can be adjusted and fixed at multiple different angular dimensions, which is beneficial for the turning point and turning angle of the turning optical path to reach an ideal state.

[0115] Please refer to Figure 9 , in this embodiment, the light guiding module 50 includes an objective lens assembly 51, dichroic mirror assemblies 52, 53, 54. The objective lens assembly 51 is used to guide the illumination laser from the illumination module 20 to the sequencing chip on the carrying part 34. The dichroic mirror assembly 52 is located on the optical path of the illumination laser and the detected fluorescence, and is used to reflect the illumination laser to the sequencing chip on the carrying part 34, and is also used to reflect the detected fluorescence to the dichroic mirror assembly 53. The dichroic mirror assembly 53 is used to reflect the detected fluorescence to the dichroic mirror assembly 54, and is used to transmit the focusing beam from the focusing module 60 or reflected from the sequencing chip. The dichroic mirror assembly 64 is used to selectively reflect the detected fluorescence to the imaging channel 401 or transmit it to the imaging channel 402 according to the wavelength of the detected fluorescence.

[0116] Please refer to Figure 15 , the objective lens assembly 51 includes an objective lens 511, a fixing base 512, an adjusting base 513 and a motor 514. An installation hole 136 is provided on the top plate 13. The fixing base 512 fixes the objective lens 511 on the top plate 13, and the objective lens 511 passes through the installation hole 136. The adjusting base 513 is connected to the motor 514 and is used to drive the objective lens 511 to move in a direction perpendicular to the top plate 13 (i.e., parallel to the optical axis of the objective lens) under the drive of the motor 514, so as to adjust the concentricity of the objective lens 511 in the entire optical system and the perpendicularity of the objective lens 511 relative to the object plane and the image plane, and the adjustment accuracy can reach the nanometer level. At the same time, it can also cooperate with the focusing module 60 to achieve fast and high-precision focusing in a direction perpendicular to the top plate 13. In this embodiment, the motor 514 is a voice coil motor, which has small vibration and is beneficial to keeping the objective lens 511 stable during the displacement of the objective lens 511.

[0117] In this embodiment, the objective lens 511 is connected to the fixed seat 512 through a precision thread, and the fixed seat 512 and the adjustment seat 513 are connected through three groups of precision adjustment mechanisms 515. The three groups of adjustment mechanisms 515 have basically the same structure and function. Each group of adjustment mechanisms 515 includes a precision adjustment thread pair 5151 and two fastening screws 5152. The outer contour of the objective lens 511 is cylindrical, and the three groups of precision adjustment mechanisms 515 are evenly arranged around the circumference of the objective lens 511, that is, the three groups of adjustment mechanisms 515 are respectively located at the angular positions of 0°, 120°, and 240°. Different positioning grooves are provided on the adjustment seat 513 to achieve precise positioning and avoid damaging the installation contact surface during adjustment. On the fixed seat 512 around the circumference of the objective lens 511, auxiliary adjustment parts 516 are provided at the 60° angular positions from each group of adjustment mechanisms 515. The auxiliary adjustment parts 516 can ensure that during the precision adjustment process, after all the fastening screws are loosened, the objective lens 511 and the fixed seat 512 will not separate, that is, the objective lens 511 and the fixed seat 512 will not fall off the top plate 13, and at the same time, it can fully meet the shock absorption requirements and facilitate precision adjustment. The adjustment seat 513 together with the fixed seat 512 and the objective lens 511 are jointly installed on the motor 514. The motor 514 is fixed to the surface 132 of the top plate 13 by 4 M5 screws, avoiding interference with the optical parts on the surface 132 of the top plate, simplifying the optical layout and making the opto-mechanical structure more compact. The motor 514 can drive a 1100g load for up and down adjustment with nanometer-level precision, so as to adjust the distance between the object plane and the objective lens by adjusting the position of the objective lens 511 and improve the imaging state of the optical system.

[0118] Please refer to Figures 16 to 19 , the dichroic mirror assemblies 52, 53, and 54 have basically the same structure and function. Taking the dichroic mirror assembly 52 as an example, the dichroic mirror assembly 52 includes a dichroic mirror 521, a mirror frame 522, and an adapter block 523.

[0119] The optical imaging system 100 further includes a reference support 70 fixed to the top plate 13. The reference support 70 is an opaque housing for closing the optical path on the top plate 13 to avoid external light interfering with the optical path. And the reference support 70 is also used to install and fix the dichroic mirror assemblies 52, 53, 54 and the tube lens assembly 43, which is beneficial to streamlining the frame installation structure of the optical path.

[0120] The lens frame 522 has a mounting bracket 5221 and a connecting portion 5222. The mounting bracket 5221 is a frame structure with a mounting hole in the center, and the dichroic mirror 521 is mounted in the mounting hole. In this embodiment, there is a gap between the dichroic mirror 521 and the mounting bracket 5221, which is beneficial to reducing the stress in the direction parallel to the light-receiving surface S3 of the dichroic mirror 521. In this embodiment, the dichroic mirror 521 is fixed to the mounting bracket 5221 by injecting glue on the surface of the dichroic mirror 521 parallel to the light-receiving surface S3, which is beneficial to avoiding squeezing the dichroic mirror 521 in the direction parallel to the light-receiving surface S3 during the curing process of the glue. In other embodiments of the present application, the dichroic mirror 521 can be directly placed in the mounting hole of the mounting bracket 5221 without using other structures (such as injecting glue) for fixing. Since the dichroic mirror 521 itself has a certain inclination (the light-receiving surface S3 forms a 45° angle with the surface 132), it can also be kept in the mounting hole without falling off when directly placed.

[0121] A plurality of adjustment holes 5223 are formed on the connecting portion 5222, and the arrangement direction of the plurality of adjustment holes 5223 is perpendicular to the light-receiving surface S3 of the dichroic mirror 521. A plurality of adjustment holes 5231 corresponding to the adjustment holes 5223 one by one are formed on the adapter block 523. The aperture of the adjustment hole 5223 is slightly larger than the aperture of the adjustment hole 5231, so that the relative position of the adapter block 523 and the lens frame 522 in the direction perpendicular to the light-receiving surface S3 is adjustable.

[0122] Two positioning holes 524 are provided at the connection between the lens frame 522 and the adapter block 523, which are used to cooperate with the pin to position the installation position of the dichroic mirror 521 and set the relative rotation axis. Four locking holes 525 are also provided at the connection between the lens frame 522 and the adapter block 523, which are used to cooperate with the screw to lock the entire lens frame 522 and the adapter block 523.

[0123] In this embodiment, the adapter block 523 is connected to the reference support 70. The adapter block 523 can be displaced relative to the reference support 70 in the direction parallel to the dichroic mirror 521. In the dichroic mirror assembly 52, the adapter block 523 and the connecting portion 5222 are exposed outside the reference support 70, and the mounting bracket 5221 and the dichroic mirror 521 are received inside the reference support 70 to avoid affecting the optical path by external ambient light.

[0124] In this embodiment, by forming the connecting portion 5222 and connecting the connecting portion 5222 with the adapter block 523, the dichroic mirror assembly 52 presents an Figure 19 "L"-shaped structure as shown in the side view, which is beneficial to avoiding opening holes on the mounting bracket 5221, thereby avoiding squeezing the dichroic mirror 521 during the process of locking or adjusting the position of the dichroic mirror 521, being beneficial to releasing stress, avoiding the dichroic mirror 521 from being deformed by force, and further being beneficial to improving the imaging quality of the fluorescence image.

[0125] Please refer toFigure 20 After the light split by the dichroic mirror 521 needs to pass through the filter assembly 44 and the tube lens assembly 43 for condensing and finally enter the camera 411. The filter 441 in the filter assembly 44 is installed in front of the tube lens assembly 43 through the filter holder 442, which is easy to disassemble, install and adjust. The tube lens 431 in the tube lens assembly 43 is fixed by the flange 432. There are 4 locking threaded holes on the flange, and an L-shaped stress relief structure is adopted to avoid stress acting on the lens of the tube lens 431, causing deformation of the tube lens 431 and thus affecting the imaging quality.

[0126] Please refer to Figure 9 and Figure 20 simultaneously. In the optical imaging system 100 of this embodiment, the illumination laser emitted by the illumination module 20 includes light of two wavelengths. The light of the two wavelengths is reflected by the dichroic mirror 521 to the objective lens 511. The objective lens 511 is used to focus the illumination laser of the two wavelengths onto the sequencing chip on the carrier part 34 to form two separate light spots, respectively exciting different fluorescent groups, so that different fluorescent groups are excited to generate detection fluorescence of two different wavelengths. The detection fluorescence of the two different wavelengths is guided by the objective lens 511 to the dichroic mirror 521. The dichroic mirror 521 is used to reflect the detection fluorescence of the two wavelengths to the dichroic mirror assembly 53. The dichroic mirror assembly 53 is used to reflect the detection fluorescence of the two wavelengths to the dichroic mirror assembly 54. The dichroic mirror assembly 54 is used to reflect the detection fluorescence of one wavelength to the imaging channel 401 and transmit the detection fluorescence of the other wavelength to the imaging channel 402. The optical paths of the detection fluorescence in the two imaging channels are basically the same. Taking the imaging channel 401 as an example, the filter 441 has a high cut-off depth for light outside the preset wavelength. The detection fluorescence reflected from the dichroic mirror assembly 54 is transmitted through the filter 441 to the tube lens 431 and the mirror 421, and finally converges to the photosensitive surface of the camera 411. The camera 411 generates a fluorescence image of the nucleic acid sample according to the received detection fluorescence. In this embodiment, the optical paths of the light (illumination laser and detection fluorescence) propagating on the surface 132 of the top plate 13 are all parallel to the surface 132.

[0127] For the above optical imaging system 100 and sequencer of the present application, the main frame 10 is used to achieve precise assembly of each functional module in the optical imaging system 100 (including the illumination module 20, the stage module 30, the imaging module 40 and the light guiding module 50. The illumination module 20, the stage module 30, the imaging module 40, the light guiding module 50 and the focusing module 60). Through the hollow design of the side plate 12 and the design of the inclined part 122, the weight is reduced and the volume of the optical imaging system is reduced. Through ANSYS simulation analysis of the vibration frequency data, its first-order vibration frequency exceeds 280 HZ, greatly reducing the resonance risk caused by the internal vibration source of the optical imaging system, and through the shock absorption component 16, the vibration frequency above 20 HZ can be filtered out.

[0128] The illumination module 20 adopts a spot shaping system composed of two cylindrical lenses. The angle between the cylindrical lenses is relatively adjustable, which can shape the spot of the illumination laser from a rectangle into a line. The beam splitting component can separate the illumination areas of the red and green lasers on the sequencing chip of the bearing part 34, so that the excitation fluorescence of the illumination lasers with different wavelengths on the same area of the sequencing chip is staggered in time.

[0129] By adopting an integrated sub-micron stage module 30 with three degrees of freedom (linear translation in the first direction, linear translation in the second direction, rotation), it is possible to drive the sequencing chip to perform high-precision and accurate positioning movement. The input of focusing labor is reduced, the efficiency of the focusing work is improved, and the entire focusing system becomes more intelligent. At the same time, this four-degree-of-freedom platform has the advantages of large stiffness, strong load-bearing capacity, fast response speed, high precision, simple control, and relatively easy decoupling analysis; the entire system can achieve high-precision, high-speed, and high-response positioning movement of the multi-degree-of-freedom motion system through a fully closed-loop control method, while taking into account the requirements of practicality and system stability.

[0130] The stage module 30 includes two bearing parts 34, which can be adapted to sequencing chips with different fluxes (one sequencing chip is carried on each bearing part 34, and the fluxes of the sequencing chips on the two bearing parts 34 are different). The two bearing parts 34 can be independently leveled. Using the principle of three points determining a plane, the precise leveling of the entire surface of the sequencing chip is finally achieved by fine-tuning the three support points of the chip platform. The leveling accuracy reaches within 10 um (the height difference after leveling the entire sequencing chip). The design of independent leveling and double bearing parts can make the sequencing work more flexible, realizing the free selection of single-chip low-throughput, double-chip low-throughput, single-chip high-throughput, and double-chip high-throughput, making the sequencing more versatile.

[0131] The tube lens assembly 43 and the filter assembly 44 in the optical imaging system 100 are both installed on the reference support 70, without the need for an independent design of the mounting frame, and the overall optical path changes from two-dimensional to three-dimensional. In the tube lens assembly 43, the tube lens is fixed by a flange, and the "L" type stress release method is adopted to make the stress direction perpendicular to the lens, avoiding stress acting on the lens and causing deformation.

[0132] The angular positions of the optical elements in each module (including the illumination module 20, the stage module 30, the imaging module 40, and the light guiding module 50) in the optical path of the optical imaging system 100 can be finely adjusted, which is beneficial to ensuring the accuracy of the optical path and improving the accuracy of the fluorescence image.

[0133] Those of ordinary skill in the art of this technology should recognize that the above embodiments are only used to illustrate the present application, rather than to limit the present application. As long as within the scope of the substantial spirit of the present application, appropriate changes and variations made to the above embodiments fall within the scope of protection required by the present application.

Claims

1. An optical imaging system, characterized in that, comprising: an illumination module for emitting illumination laser; a stage module for carrying a sample, the sample carrying a fluorescent group; a light guiding module located on the optical path of the illumination laser for receiving and guiding the illumination laser to the stage module, when the illumination laser irradiates the sample, it excites the fluorescent group to generate detection fluorescence, and the light guiding module is also located on the optical path of the detection fluorescence for receiving the detection fluorescence; an imaging module for receiving the detection fluorescence from the light guiding module and generating a fluorescence image of the sample according to the detection fluorescence, the fluorescence image being used to obtain the base sequence information of the sample; and a main body frame, the illumination module, the light guiding module, the stage module and the imaging module are connected to the main body frame, and the main body frame is used to maintain the relative positions among the illumination module, the light guiding module, the stage module and the imaging module.

2. The optical imaging system according to claim 1, characterized in that, the main body frame includes: a bottom plate; two side plates, the two side plates are fixedly connected to the same surface of the bottom plate, the bottom plate and the two side plates form a receiving space, and the stage module is connected to the surface of the bottom plate where the two side plates are connected and is located in the receiving space; a top plate, fixedly connected to the side of the two side plates away from the bottom plate, the illumination module and the imaging module are respectively connected to the surface of the top plate away from the bottom plate, and part of the light guiding module is connected to the surface of the top plate away from the bottom plate.

3. The optical imaging system according to claim 2, characterized in that, a plurality of grooves are formed on the surface of the top plate facing the bottom plate, a plurality of grooves are formed on the surface of the bottom plate away from the top plate, and hollowed-out areas are respectively formed on the two side plates, and the main body frame further includes a plurality of shock absorption components fixedly connected to the two side plates.

4. The optical imaging system according to claim 3, characterized in that, each side plate includes a flat part and an inclined part connected to each other, the flat part is connected between the bottom plate and the inclined part, and the inclined part is fixedly connected to the surface of the top plate facing the bottom plate; the flat part is perpendicular to the bottom plate, and the plurality of shock absorption components are fixedly connected to the flat part; the inclined part is inclined towards the direction of the other side plate.

5. The optical imaging system according to claim 2, characterized in that, the light guiding module includes an objective lens assembly, the objective lens assembly includes an objective lens, an objective lens fixing seat, an objective lens adjusting seat and an adjusting motor, the objective lens is used to guide the illumination laser to the stage module and is used to guide the detection fluorescence to the sample; the objective lens fixing seat is fixedly connected to the top plate, and the adjusting motor is connected to the objective lens adjusting seat for driving the objective lens to displace in a direction perpendicular to the top plate.

6. The optical imaging system according to claim 2, characterized in that, the light guiding assembly includes a dichroic mirror assembly, and the dichroic mirror assembly includes: Dichroic mirror, frame and adapter block, the dichroic mirror is installed in the frame, and the frame is connected to the adapter block; The frame can be displaced relative to the adapter block in a direction perpendicular to the dichroic mirror.

7. The optical imaging system according to claim 2, characterized in that, The imaging module includes a mirror, a mounting base, a horizontal adjustment member, a vertical adjustment member and a fixing frame, the mirror is installed on the fixing frame, and the fixing frame, the horizontal adjustment member and the vertical adjustment member are respectively connected to the mounting base; The horizontal adjustment member is used to adjust the displacement of the mounting base, the fixing frame and the mirror in a direction parallel to the top plate, and the vertical adjustment member is used to adjust the displacement of the fixing frame and the mirror in a direction perpendicular to the top plate.

8. The optical imaging system according to claim 2, characterized in that, The imaging module includes a camera assembly, and the camera assembly includes a camera, a camera fixing seat, a camera base, a front-back adjustment member, a left-right adjustment member, an up-down adjustment member and a rotation adjustment member; The camera is installed on the camera base, the camera fixing seat is connected to the surface of the top plate away from the bottom plate, the camera base is connected to the surface of the camera fixing seat away from the top plate, the left-right adjustment member is connected to the camera fixing seat, and the front-back adjustment member, the up-down adjustment member and the rotation adjustment member are connected to the camera base; The left-right adjustment member is used to adjust the displacement of the camera in a direction perpendicular to the optical axis and parallel to the top plate, the front-back adjustment member is used to adjust the displacement of the camera relative to the camera fixing seat in a direction parallel to the optical axis, the up-down adjustment member is used to adjust the displacement of the camera in a direction perpendicular to the optical axis and the top plate, and the rotation adjustment member is used to adjust the rotation of the camera around an axis parallel to the optical axis.

9. The optical imaging system according to claim 2, characterized in that, The stage module includes a first displacement part, a second displacement part, a rotation part and two carrying parts stacked in sequence, the two carrying parts are located on one side of the rotation part away from the bottom plate, and the two carrying parts are respectively used to carry the sequencing chip with the sample; The first displacement part and the second displacement part are respectively used to drive the sequencing chip to linearly displace in two mutually perpendicular directions, and the rotation part is used to drive the sequencing chip to rotate in a plane parallel to the bottom plate.

10. A sequencer, characterized in that, comprising: The optical imaging system according to any one of claims 1-9; An image processing system, electrically connected to the imaging module, for obtaining the base sequence information of the sample according to the fluorescence image generated by the imaging module.

Images