Micro-droplet screening equipment and system

Abstract

The invention discloses micro-droplet screening equipment and a micro-droplet screening system. The micro-droplet screening equipment comprises an upper computer (1), an optical signal detection device (2), a signal processor (3) and an electric screening device (4), the optical signal detection device (2) is used for acquiring an optical signal of the to-be-detected liquid drop and converting the optical signal into an electric signal of the to-be-detected liquid drop. The signal processor (3) is electrically connected with the optical signal detection device (2), and the signal processor (3) is used for receiving and processing an electric signal of the liquid drop to be detected and sending a screening instruction to the electric screening device (4) according to the strength of the electric signal. The electric filter (4) is electrically connected with the signal processor (3), and the electric filter (4) controls the to-be-detected liquid drops in the micro-fluidic sorting chip (5) to deflect to the corresponding flow channels according to the screening instruction so as to complete screening of the to-be-detected liquid drops. The upper computer (1) is electrically connected with the signal processor (3), and the upper computer (1) is used for issuing a screening instruction and setting related screening parameters. The micro-droplet screening equipment is high in integration level and automation degree, and the convenience of micro-droplet screening is greatly improved.

Description

Micro-droplet screening equipment and systems Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a micro-droplet screening device and system. Background Art

[0002] The high-throughput screening technology of microdroplets is to encapsulate single cells and biochemical reaction reagents in monodisperse droplets. After the droplets react under certain conditions, there will be a special light signal change in the positive droplets containing target cells. This signal change is different from other empty droplets or droplets encapsulated with non-target cells. The droplets pass through the microfluidic sorting chip, and the optical signals are collected. By analyzing the optical signals, the sorting threshold is defined. Positive droplets exceeding the threshold will trigger a positive sorting electric pulse when passing through the detection area of ​​the microfluidic chip, and the corresponding positive droplets will be electrically deflected to the microfluidic chip collection channel, thereby realizing the sorting of positive cells.

[0003] Microdroplet screening technology can quickly encapsulate single cells in a picoliter volume, and the average daily droplet detection throughput can reach 10 7 The tiny reaction systems formed by oil-in-water droplets avoid contamination between different samples, enabling high-throughput cell function detection and sorting at the single-cell level. Compared with flow cytometry, microdroplet screening technology can detect not only intracellular and cell surface signals, but also cell secretions and cell lysis products. It can meet the needs of important industries such as monoclonal antibody screening, tumor immunotherapy cell preparation, industrial strain screening, and enzyme screening, and has a wide range of commercial applications.

[0004] Existing technical means that can be used for monoclonal antibody screening, tumor immunotherapy cell preparation, industrial strain screening, and enzyme directed evolution include: flow cytometry, microplate method, and water-in-oil-in-water tandem flow cytometry. These technical means usually have defects such as low integration and automation.

[0005] Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the existing screening technology, the present invention provides a micro-droplet screening device and system.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] In a first aspect, a micro-droplet screening device is provided, the micro-droplet screening device comprising a host computer, an optical signal detection device, a signal processor, and an electrical screener;

[0009] The optical signal detection device is used to obtain an optical signal of the droplet to be detected and convert the optical signal into an electrical signal of the droplet to be detected;

[0010] The signal processor is electrically connected to the optical signal detection device, and is used to receive and process the electrical signal of the droplet to be detected, and send a screening instruction to the electrical filter according to the intensity of the electrical signal;

[0011] The electric filter is electrically connected to the signal processor, and controls the droplets to be tested in the microfluidic sorting chip to be deflected to the corresponding flow channel according to the screening instruction, so as to complete the screening of the droplets to be tested;

[0012] The host computer is electrically connected to the signal processor, and is used to issue the screening instruction and set relevant screening parameters.

[0013] Optionally, the optical signal includes at least one of a fluorescence signal, a scattered light signal and an absorbed light signal.

[0014] Optionally, the optical signal detection device includes a first light source emitter, a first light path transmission component, a first light path receiving component, and a first photomultiplier tube;

[0015] The first light source transmitter is provided with a first light path transmitting component and a first light path receiving component correspondingly;

[0016] The first light source emitter excites the optical signal of the droplet to be measured through the first optical path transmission component;

[0017] The first light path receiving component is used to obtain the fluorescent signal processed by the filtered light;

[0018] Wherein, the first optical path transmission component includes a first beam combiner, a cylindrical lens, and an objective lens, and the first optical path receiving component includes a first dichroic mirror, a first plano-convex lens, and a first filter;

[0019] The first photomultiplier tube converts the fluorescence signal into an electrical signal.

[0020] Optionally, the optical signal detection device includes a second light source transmitter, a second optical path transmission component, a first optical fiber receiving component, and a second photomultiplier tube;

[0021] The second light source emitter is correspondingly provided with a second light path transmission component;

[0022] The second light source emitter excites the optical signal of the droplet to be measured through the second optical path transmission component;

[0023] The first optical fiber receiving component is used to obtain the scattered light signal processed by the filtered light;

[0024] Wherein, the second optical path transmission component includes a second beam combiner, a cylindrical lens, and an objective lens, and the first optical fiber receiving component includes an optical fiber receiver, a second plano-convex lens, and a second filter;

[0025] The second photomultiplier tube converts the scattered light signal into an electrical signal.

[0026] Optionally, the optical signal detection device includes a third light source transmitter, a first optical fiber transmission component, a second optical fiber receiving component, and a third photomultiplier tube;

[0027] The first optical fiber transmission component and the second optical fiber receiving component are respectively connected to the first optical fiber interface and the second optical fiber interface distributed on both sides of the flow channel of the microfluidic sorting chip;

[0028] The third light source emitter emits light to the first optical fiber interface through the first optical fiber transmission component to stimulate the optical signal of the droplet to be measured;

[0029] The second optical fiber receiving component is used to obtain the absorption light signal after the filtered light processing;

[0030] Wherein, the second optical fiber receiving assembly includes an optical fiber receiver, a third plano-convex lens and a third filter;

[0031] The third photomultiplier tube converts the absorbed light signal into an electrical signal.

[0032] Optionally, the number of the first light source emitter, the second light source emitter and the third light source emitter is multiple;

[0033] The wavelength band of the light emitted by each first light source emitter is not completely the same, the wavelength band of the light emitted by each second light source emitter is not completely the same, and the wavelength band of the light emitted by each third light source emitter is not completely the same;

[0034] The wavelength band of the emitted light of the first light source emitter and the filtering parameters of the first filter match the fluorescence signal; the wavelength band of the emitted light of the second light source emitter and the filtering parameters of the second filter match the scattered light signal; the wavelength band of the emitted light of the third light source emitter and the filtering parameters of the third filter match the absorbed light signal.

[0035] Optionally, the signal processor is used to determine, based on the intensity of the electrical signal of the droplet to be tested, a branch channel that matches the intensity of the electrical signal, and send the screening instruction to the electrical filter.

[0036] Optionally, the signal processor is used to send a movement instruction to a host computer when determining that the droplet to be tested is a positive droplet;

[0037] The host computer controls the movement of the micro-droplet collecting device according to the movement instruction.

[0038] Optionally, the micro-droplet collecting device includes a plurality of collecting chambers;

[0039] The host computer controls the movement of the micro-droplet collecting device when the number of droplets in a collection chamber reaches a preset number. Optionally, the micro-droplet screening device further includes an injection device, which includes a pressure pump, a syringe, and an injection controller;

[0040] The liquid injection device is electrically connected to the host computer, and the host computer controls the liquid injection device to inject the dispersed phase and the droplets to be tested into the microfluidic sorting chip;

[0041] The syringe is installed in the pressure pump, and the injection controller controls the pressure pump to provide power to the syringe;

[0042] An angle is set between the syringe and the horizontal plane.

[0043] Optionally, the host computer is used to visually display the optical signal when receiving the optical signal of the droplet to be measured;

[0044] The host computer is also used to set parameters for the optical signal detection device, the signal processor and the electrical filter.

[0045] Optionally, the micro-droplet screening device further comprises a light-shielding housing;

[0046] The optical signal detection device is arranged in the light-shielding housing to block interference from ambient light.

[0047] In a second aspect, a micro-droplet screening system is provided, the micro-droplet screening system comprising the microfluidic sorting chip and any of the above-mentioned micro-droplet screening devices, the microfluidic sorting chip comprising an optical fiber channel, a sorting component, and at least two branch channels;

[0048] The optical fiber channel is connected to the optical fiber interface for transmitting optical signals;

[0049] The sorting component is used to sort the droplets to be tested into corresponding branch channels when receiving a deflection instruction.

[0050] The beneficial effect of the present invention is that the screening of the droplets to be tested is achieved by providing a host computer, an optical signal detection device, a signal processor, and an electrical filter. Specifically, the optical signal of the droplets to be tested is obtained by the optical signal detection device, and the optical signal is converted into an electrical signal of the droplets to be tested. The signal processor receives and processes the electrical signal of the droplets to be tested, and sends a screening instruction to the electrical filter according to the intensity of the electrical signal. The electrical filter controls the deflection of the droplets to be tested in the microfluidic sorting chip to the corresponding flow channel according to the screening instruction, and automatically completes the screening of the droplets to be tested. This provides a micro-droplet screening device with high integration and high automation, greatly improving the convenience of micro-droplet screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG1 is a schematic diagram of a micro-droplet screening device according to an embodiment of the present invention.

[0052] FIG2 is a schematic diagram of a signal processing feedback control board according to an embodiment of the present invention.

[0053] FIG3 is a schematic diagram of a microfluidic sorting chip according to an embodiment of the present invention.

[0054] FIG. 4 is a schematic diagram of an optical signal detection device according to an embodiment of the present invention.

[0055] FIG5 is a schematic diagram of a liquid injection device according to an embodiment of the present invention.

[0056] FIG6 is a schematic diagram of the device system software according to an embodiment of the present invention.

[0057] FIG7 is a schematic diagram of the overall structure of the micro-droplet screening device according to an embodiment of the present invention.

[0058] FIG8 is a scatter plot of droplet data according to an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0060] Figure 1 is a schematic diagram of a micro-droplet screening device provided by an exemplary embodiment of the present invention, which includes a host computer 1, an optical signal detection device 2, a signal processor 3, and an electrical filter 4. The optical signal detection device 2 is used to obtain the optical signal of the droplet to be tested and convert the optical signal into the electrical signal of the droplet to be tested. The signal processor 3 is electrically connected to the optical signal detection device 2, and the signal processor 3 is used to receive and process the electrical signal of the droplet to be tested, and send a screening instruction to the electrical filter 4 according to the intensity of the electrical signal. The electrical filter 4 is electrically connected to the signal processor 3, and the electrical filter 4 controls the deflection of the droplet to be tested in the microfluidic sorting chip 5 to the corresponding flow channel according to the screening instruction to complete the screening of the droplet to be tested. The host computer 1 is electrically connected to the signal processor 3, and is used to issue the screening instruction and set the relevant screening parameters. Among them, the relevant screening parameters include: droplet judgment conditions, the amplitude, frequency and duration of the electric pulse of the electrical deflection, etc.

[0061] As shown in Figure 2, the signal processor 3 can be a signal processing feedback control board, comprising signal input ports 2121-2128, a signal processing center 22, a deflection electric pulse 231, and a droplet distribution electric pulse 232. During operation, the electrical signal of the droplet to be tested is input through the signal input ports 2121-2128. The signal processing center 22 includes a droplet signal extraction module, a droplet signal feature calculation module, a droplet identification module, and an electric pulse triggering module, which are used to process the electrical signals input from the control board's signal input ports 2121-2128. These modules identify the desired droplet to be tested. After identification, a screening instruction is sent to the electric filter 4, which can be a deflection electric pulse 231. The signal processing feedback control board also includes an ADC module consisting of multiple ADCs (Analog-to-Digital Converters). The ADC module can simultaneously and continuously sample the first, second, and third photomultiplier tubes. The ADC module stores the digital signals in memory for data analysis and processing. The signal processing feedback control board can also filter background signals and simultaneously collect characteristic values ​​of multiple signals (different optical signals, or parameters of different bands of the same optical signal), including but not limited to peak value, average value, signal width, and perform signal calculations within and between channels to screen the droplets to be tested.

[0062] As shown in Figure 3, the micro-droplet screening device requires the use of a microfluidic sorting chip 5 when performing droplet screening. The microfluidic sorting chip 5 includes at least one droplet inlet, at least one oil phase inlet, at least two outlets (a collection port and a waste port), a screening electrode, a shielding electrode, and at least one optical fiber insertion port. For example, FIG3 shows a microfluidic sorting chip 5 suitable for a micro-droplet screening device, including a sheath liquid inlet (511, 512), a droplet phase inlet (513), a positive droplet outlet (521), a negative droplet outlet (522), a low-melting-point metal infusion port (531, 533, 541, 544), an atmospheric pressure connection port (532, 534), a wire insertion port (542, 543), an optical fiber insertion port (551, 552, 553), a PDMS infusion port (561, 562, 563), a main flow path (57), a branch flow path (518, 519), a pressure relief channel (520), shielding electrodes (5211, 5212), and a screening electrode (54).

[0063] The micro-droplets to be tested flow into the microfluidic sorting chip 5 from the droplet phase inlet (513). When the micro-droplets to be tested pass through the detection area of ​​the microfluidic sorting chip 5, the optical signal of each micro-droplet to be tested is detected by the optical signal detection device 2, and the optical signal is converted into an electrical signal (such as a voltage signal) of the droplet to be tested. The signal processor determines whether to send a screening instruction based on the intensity of the electrical signal (such as the magnitude of the voltage signal). If the intensity of the electrical signal meets the preset sorting threshold, the screening instruction will be sent to the electrical filter 4. The electrical filter 4 will trigger a deflection electric pulse, which can realize the sorting of positive droplets into the corresponding branch channel, such as the branch flow path (518, 519). The positive droplets are the micro-droplets to be tested that need to be screened out.

[0064] In this embodiment, a host computer 1, an optical signal detection device 2, a signal processor 3, and an electrical filter 4 are integrated to screen droplets to be tested. This provides a highly integrated and automated micro-droplet screening device, greatly improving the convenience of micro-droplet screening.

[0065] Optionally, the optical signal includes at least one of a fluorescent signal, a scattered light signal, and an absorbed light signal. The fluorescent signal, scattered light signal, and absorbed light signal are selected for screening based on the different characteristics of the microdroplets to be tested. For example, a first microdroplet to be tested may be identified as a positive microdroplet based on the optical signal intensities of both the fluorescent signal and the scattered light signal, while a second microdroplet to be tested may be identified as a positive microdroplet based on the optical signal intensities of the fluorescent signal, the scattered light signal, and the absorbed light signal.

[0066] Optionally, referring to FIG4 , the optical signal detection device 2 includes a first light source emitter (at least one first light source emitter is arbitrarily selected from 212 to 215 ), a first optical path transmission component, a first optical path receiving component, and a first photomultiplier tube (a first photomultiplier tube corresponding to the first light source emitter is selected from 281 to 284 ). The first light source emitter is provided with a first optical path transmission component and a first optical path receiving component. The first light source emitter excites the optical signal of the droplet to be measured through the first optical path transmission component. The first optical path receiving component is used to obtain the fluorescent signal processed by the filtered light. The first optical path transmission component includes a first beam combiner (select the first beam combiner corresponding to the first light source emitter from 221 to 224), a cylindrical lens 23, and an objective lens 293. The first optical path receiving component includes a first dichroic mirror (select the first dichroic mirror corresponding to the first light source emitter from 241 and 241 to 246), a first plano-convex lens (select the plano-convex lens corresponding to the first light source emitter from 261 to 268 as the first plano-convex lens), and a first filter (select the filter corresponding to the first light source emitter from 271 to 278 as the first filter). The first photomultiplier tube converts the fluorescence signal into an electrical signal.

[0067] In addition to the above-mentioned components, the optical signal detection device 2 also includes an illumination light source 295, a stage 294, a cylindrical lens 291, and a high-speed camera 292. Before detecting the fluorescence signal, the microfluidic sorting chip 5 is placed on the stage. When the high-speed camera observes that the droplets are arranged in a single row in the flow channel of the microfluidic sorting chip 5 and pass through with stable spacing, it means that the fluorescence signal can be measured. The first light source emitter is used to emit light sources such as laser and infrared light. The type of light emitted by the first light source is not limited here. The first optical path transmission component includes a first beam combiner, a cylindrical lens, and an objective lens. The first optical path transmission component is used to transmit the light path emitted by the first light source to the stage. The first optical path receiving component includes a first dichroic mirror, a first plano-convex lens, and a first filter, which is used to obtain the fluorescence signal after filtering. After receiving the fluorescence signal, the first photomultiplier tube converts the fluorescence signal into an electrical signal, which can be a voltage value. When different fluorescence signals from the same droplet need to be measured, multiple first light source emitters can be provided, with the number of first optical path transmission components, first optical path receiving components, and first photomultiplier tubes corresponding to the number. The wavelength of the light from the first light source emitter can be adjusted based on measurement requirements, and the filtering parameters of the first filter correspond to the wavelength of the light from the first light source emitter.

[0068] Optionally, referring to FIG4 , the optical signal detection device 2 includes a second light source transmitter (at least one second light source transmitter is selected from 212 to 215 ), a second optical path transmission component, a first optical fiber receiving component, and a second photomultiplier tube (at least one photomultiplier tube is selected from 285 to 288 ). The second light source transmitter is provided with a second optical path transmission component. The second light source transmitter excites the optical signal of the droplet to be detected through the second optical path transmission component. The first optical fiber receiving component is used to obtain the scattered light signal after filtering. The second transmission component includes a second beam combiner (a second beam combiner corresponding to the second light source transmitter is selected from 221 to 224 ), a cylindrical lens 23 , and an objective lens 293 . The first optical fiber receiving component includes a first optical fiber receiver (at least one first optical fiber receiver is selected from 252 to 255 ), a second plano-convex lens (a plano-convex lens corresponding to the first optical fiber receiver is selected from 265 to 268 as the second plano-convex lens), and a second filter (a filter corresponding to the first optical fiber receiver is selected from 275 to 278 as the second filter). The second photomultiplier tube converts the scattered light signal into an electrical signal.

[0069] In addition to the above-mentioned components, the optical signal detection device 2 also includes an illumination light source 295, a stage 294, a cylindrical lens 291, and a high-speed camera 292. Before detecting the scattered light signal, the microfluidic sorting chip 5 needs to be placed on the stage. When the high-speed camera observes that the droplets are arranged in a single row in the flow channel of the microfluidic sorting chip 5 and the spacing passes stably, it means that the scattered light signal can be measured. The second light source transmitter is used to emit light sources such as laser and infrared light. The type of light emitted by the second light source is not limited here. The second optical path transmission component includes a second beam combiner, a cylindrical lens, and an objective lens. The first optical fiber receiving component includes an optical fiber receiver, a second plano-convex lens, and a second filter. The optical fiber receiver is connected to the interface of any optical fiber insertion port of the microfluidic sorting chip 5. The optical fiber receiving component is used to obtain the scattered light signal after filtering. After receiving the scattered light signal, the photomultiplier tube converts the scattered light signal into an electrical signal, which can be a voltage value. When measuring different scattered light signals from the same droplet, multiple second light source transmitters can be provided, with the number of second optical transmission components, first optical fiber receiving components, and photomultiplier tubes corresponding to the number. The wavelength of the light from the second light source transmitter can be adjusted based on measurement requirements, and the filtering parameters of the second filter correspond to the wavelength of the light from the second light source transmitter.

[0070] Optionally, referring to FIG4 , the optical signal detection device 2 includes a third light source transmitter 211 and its optical fiber interface 251, a first optical fiber transmission component, a second optical fiber receiving component, and a third photomultiplier tube (at least one photomultiplier tube is arbitrarily selected from 285 to 288). The first optical fiber transmission component and the second optical fiber receiving component are respectively connected to the first optical fiber interface and the second optical fiber interface distributed on both sides of the flow channel of the microfluidic sorting chip 5. The third light source transmitter 211 transmits light to the first optical fiber interface through the first optical fiber transmission component to excite the optical signal of the droplet to be detected. The second optical fiber receiving component is used to obtain the absorption light signal after filtering. Among them, the second optical fiber receiving component includes a second optical fiber receiver (at least one second optical fiber receiver is arbitrarily selected from 252 to 255), a third plano-convex lens (a plano-convex lens corresponding to the second optical fiber receiver is selected from 265 to 268 as the third plano-convex lens) and a third filter (a filter corresponding to the second optical fiber receiver is selected from 275 to 278 as the third filter), and the third photomultiplier tube converts the absorption light signal into an electrical signal.

[0071] In addition to the above-mentioned components, the optical signal detection device 2 also includes an illumination light source 295, a stage 294, a tube mirror 291, and a high-speed camera 292. Before detecting the absorption light signal, the microfluidic sorting chip 5 needs to be placed on the stage. When the high-speed camera observes that the droplets are arranged in a single row in the flow channel of the microfluidic sorting chip 5 and the spacing passes stably, it means that the absorption light signal can be measured. The third light source transmitter is used to emit light sources such as laser and infrared light. The type of light emitted by the third light source is not limited here. The first optical fiber transmission component and the second optical fiber receiving component are respectively connected to the first optical fiber interface and the second optical fiber interface distributed on both sides of the flow channel of the microfluidic sorting chip 5. The third light source transmitter transmits light to the first optical fiber interface through the first optical fiber transmission component to excite the optical signal of the droplet to be measured. The second optical fiber receiving component is used to obtain the absorption light signal after filtered light processing.

[0072] Optionally, there are multiple first light source emitters, second light source emitters, and third light source emitters. The wavelength band of the light emitted by each first light source emitter is not exactly the same, the wavelength band of the light emitted by each second light source emitter is not exactly the same, and the wavelength band of the light emitted by each third light source emitter is not exactly the same. The wavelength band of the light emitted by the first light source emitter and the filtering parameters of the first filter match the fluorescent signal, the wavelength band of the light emitted by the second light source emitter and the filtering parameters of the second filter match the scattered light signal, and the wavelength band of the light emitted by the third light source emitter and the filtering parameters of the third filter match the absorbed light signal.

[0073] Among them, when the number of the first light source emitter, the second light source emitter and the third light source emitter is multiple, the fluorescence signal, scattered light signal and absorption light signal of the same droplet to be tested, or any one of the three, can be detected simultaneously by the optical signal detection device 2. By setting the first light source emitter, the second light source emitter and the third light source emitter and the corresponding required components, fluorescence signals of different bands, scattered light signals and absorption light signals of different bands can also be detected simultaneously. The power of the first light source emitter, the second light source emitter and the third light source emitter can be adjusted, usually between 0 milliwatts (mW) and 100 milliwatts (mW). The first light source emitter, the second light source emitter and the third light source emitter can be synthesized into an optical path through a beam combiner and irradiated into the flow channel of the microfluidic sorting chip 5 through an objective lens. The droplet passes through the laser position of the flow channel to generate an excited optical signal.

[0074] In this embodiment, the fluorescence signal, scattered light signal and absorbed light signal of the droplet to be tested are detected simultaneously, which satisfies the detection of multiple optical signals of the droplet to be tested in one experiment, and provides a highly integrated and highly automated micro-droplet screening device, which greatly improves the convenience and diversity of micro-droplet screening.

[0075] Optionally, the signal processor 3 is configured to send a movement instruction to the host computer 1 when determining that the droplet to be tested is a positive droplet, and the host computer 1 controls the movement of the micro-droplet collecting device according to the movement instruction.

[0076] 1 and 2 , the signal processor 3 may be a signal processing feedback control board. When the droplet to be tested is determined to be a positive droplet through analysis, a movement instruction is sent to the host computer 1. The host computer 1 controls the movement of the micro-droplet collecting device 6 according to the movement instruction. The movement instruction may emit a deflection electric pulse 231 for the droplet.

[0077] Optionally, the micro-droplet collecting device 6 includes a plurality of collecting chambers, and the host computer 1 controls the micro-droplet collecting device to move when the number of droplets in a collecting chamber reaches a preset number.

[0078] Wherein, referring to Fig. 1, micro-droplet collecting device 6 comprises oil droplet detection sensor 601, and when oil droplet detection sensor 601 detects droplets flowing out from the hose, trigger signal is generated. Host computer 1 can control electric loading platform, and micro-droplet collecting device 6 can be placed on electric loading platform, and micro-droplet collecting device 6 can be 96 orifice plates or 384 orifice plates (also can be orifice plates with other hole numbers), and whether to move is determined by the result of optical signal analysis, deflection instruction (for example, deflection electric pulse 231) and the trigger signal of oil droplet detection sensor 601. In the actual detection process, it can also be arranged according to actual demand to detect that each orifice plate collects a preset number of droplets and moves. Waste liquid tank 602 is used to collect unscreened discarded droplets.

[0079] In this embodiment, automatic collection of droplets is achieved, providing a highly integrated and automated micro-droplet screening device, which greatly improves the convenience and diversity of micro-droplet screening.

[0080] Optionally, as shown in Figure 5 , the micro-droplet screening apparatus further includes an injection device 7 , which comprises a pressure pump, syringes 2111-2113, and an injection controller 24 . The injection device is electrically connected to the host computer 1 , which controls the injection device to inject the dispersed phase and droplets to be tested into the microfluidic sorting chip 5 . The syringe is mounted in the pressure pump, and the injection controller controls the pressure pump to provide power to the syringe. The syringe is positioned at an angle to the horizontal plane.

[0081] The injection device includes multiple precision pressure pumps and injection controllers. The pressure pumps can be driven by a stepper motor. Syringes of different sizes, ranging from 0.5mL to 100mL, can be installed according to test requirements. The injection speed can be controlled from 1nL / min to 200mL / min. It also has both push and pull functions to meet the droplet preparation and screening needs of different samples. In actual use, the sample to be tested can be infused into a disposable syringe to avoid cross-contamination of different batches of experimental samples. The sample in the syringe is connected to the microfluidic chip via a hose, and the installed syringe forms an angle with the horizontal plane.

[0082] In this embodiment, the injection device is controlled by the host computer 1, and the screening requirements of different samples are met, providing a micro-droplet screening device with high integration and high automation, which greatly improves the convenience and diversity of micro-droplet screening.

[0083] Optionally, the host computer 1 is used to visually display the optical signal when receiving the optical signal of the droplet to be detected. The host computer 1 is also used to set parameters for the optical signal detection device 2, the signal processor 3 and the electrical filter 4.

[0084] FIG6 shows the device system software applicable to the host computer 1, including a microfluidic sorting chip stage movement parameter setting module 111 (for controlling the movement of the stage in the X, Y, and Z directions), a light source transmitter power setting module 112, a pressure pump operation parameter setting module 113, a signal source selection / signal source gain setting module 114, a sorting threshold setting module 115, a sorting electric pulse amplitude / duration setting module 116, and a single droplet dispensing stage movement parameter setting module 117. The required parameters are read in real time via a high-speed camera monitoring interface 121 and an optical visualization display interface 122 (for visual display of single-channel and multi-channel optical signals).

[0085] In this embodiment, through the parameter setting and visual display of the equipment system software, it is convenient to observe the display interface and adjust the parameters at any time during the detection process, providing a highly integrated and highly automated micro-droplet screening device, which greatly improves the convenience and diversity of micro-droplet screening.

[0086] Optionally, the micro-droplet screening device further includes a light-shielding housing, and the optical signal detection device 2 is disposed in the light-shielding housing to block interference from ambient light.

[0087] Figure 7 shows the overall structure of the micro-droplet screening device, which includes a light-shielding housing 81 and a frame 82, on which the micro-droplet screening device is placed. During operation, the light-shielding housing 81 blocks interference from ambient light, ensuring that the micro-droplet screening device is not affected by ambient light even in non-darkroom working environments.

[0088] In this embodiment, by providing a light-shielding housing, the interference with the fluorescence signal, scattered light signal and absorbed light signal in actual measurement is reduced, and a highly integrated and automated micro-droplet screening device is provided, which greatly improves the convenience and diversity of micro-droplet screening.

[0089] Optionally, the micro-droplet screening device also includes a power supply system, which provides power supply for all sub-devices that require power, such as the high-speed camera, the first light source emitter, the second light source emitter, the third light source emitter, the pressure pump, the electric stage, etc., and provides adjustable gain voltage output for the multi-channel photomultiplier tubes.

[0090] In the example of screening E. coli droplets:

[0091] (1) Screening preparation stage: The plasmid containing the red fluorescent protein gene was transformed into Escherichia coli. After overnight culture on a plate, a single colony was picked and cultured in liquid LB at 37°C, 220 rpm. The seed solution was transferred to LB medium at a ratio of 1%, and shaken at 37°C, 220 rpm to an OD600 of 0.6. The bacteria were collected and centrifuged at 1000g for 5 minutes. The bacteria were washed three times with autoinduction medium, and then spun down and diluted to an OD600 of 0.1 with autoinduction medium. The suspended bacteria were encapsulated by the oil phase to form microdroplets with a droplet size of 20 μm. At this concentration, the proportion of droplets without E. coli was 74%. After the E. coli were encapsulated in the droplets, the droplets were cultured at 37°C. The E. coli multiplied within the droplets and expressed red fluorescent protein.

[0092] (2) Adjustment stage: Place the microfluidic sorting chip on the stage, adjust the movement of the stage so that the chip detection and sorting area is within the field of view of the high-speed camera, install the syringe containing droplets and oil phase on the pressure pump, and connect the syringe outlet to the microfluidic sorting chip through a hose. Adjust the droplet phase flow rate to 15μL / h, and the two sheath liquid phase flow rates are both 300uL / h. When the high-speed camera observes that the droplets are arranged in a single row in the flow channel and the spacing is stable, start the first light source emitter and the second light source emitter, adjust the photomultiplier tube gain value, and collect the scattered light signal and red fluorescent protein signal data of the bacteria in the droplets.

[0093] (3) Analysis stage: See Figure 8 for a scatter plot of the collected droplet data. The horizontal axis is the voltage parameter of the droplet scattering signal, and the vertical axis is the voltage parameter of the red fluorescent protein signal in the droplet. The box in the figure is used to define the sorting threshold range. After the sorting threshold is determined, when the detected droplet signal value is within the threshold range, it will be judged as a positive droplet. The signal processor generates a screening instruction, and the positive droplet is deflected under the dielectrophoretic force and enters the corresponding branch channel. At the same time, the droplet distribution electric pulse controls the movement of the electric stage to collect the positive droplets into the micro-droplet collection device, thereby realizing the collection of positive droplets.

[0094] Although the above describes specific embodiments of the present invention, it should be understood by those skilled in the art that these are merely illustrative and that various changes or modifications may be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is defined by the appended claims.

Claims

1. A micro-droplet screening device, characterized in that: The micro-droplet screening device includes a host computer, an optical signal detection device, a signal processor, and an electrical screener; The optical signal detection device is used to obtain an optical signal of the droplet to be detected and convert the optical signal into an electrical signal of the droplet to be detected; The signal processor is electrically connected to the optical signal detection device, and is used to receive and process the electrical signal of the droplet to be detected, and send a screening instruction to the electrical filter according to the intensity of the electrical signal; The electric filter is electrically connected to the signal processor, and controls the droplets to be tested in the microfluidic sorting chip to be deflected to the corresponding flow channel according to the screening instruction, so as to complete the screening of the droplets to be tested; The host computer is electrically connected to the signal processor, and is used to issue the screening instruction and set relevant screening parameters.

2. The micro-droplet screening device according to claim 1, characterized in that: The optical signal includes at least one of a fluorescence signal, a scattered light signal and an absorbed light signal.

3. The micro-droplet screening device according to claim 2, characterized in that: The optical signal detection device includes a first light source emitter, a first light path transmission component, a first light path receiving component, and a first photomultiplier tube; The first light source transmitter is provided with a first light path transmitting component and a first light path receiving component correspondingly; The first light source emitter excites the optical signal of the droplet to be measured through the first optical path transmission component; The first light path receiving component is used to obtain the fluorescent signal processed by the filtered light; Wherein, the first optical path transmission component includes a first beam combiner, a cylindrical lens, and an objective lens, and the first optical path receiving component includes a first dichroic mirror, a first plano-convex lens, and a first filter; The first photomultiplier tube converts the fluorescence signal into an electrical signal.

4. The micro-droplet screening device according to claim 2, wherein: The optical signal detection device 2 includes a second light source transmitter, a second optical path transmission component, a first optical fiber receiving component, and a second photomultiplier tube; The second light source emitter is correspondingly provided with a second light path transmission component; The second light source emitter excites the optical signal of the droplet to be measured through the second optical path transmission component; The first optical fiber receiving component is used to obtain the scattered light signal processed by the filtered light; Wherein, the second optical path transmission component includes a second beam combiner, a cylindrical lens, and an objective lens, and the first optical fiber receiving component includes an optical fiber receiver, a second plano-convex lens, and a second filter; The second photomultiplier tube converts the scattered light signal into an electrical signal.

5. The micro-droplet screening device according to claim 2, characterized in that: The optical signal detection device includes a third light source transmitter, a first optical fiber transmission component, a second optical fiber receiving component, and a third photomultiplier tube; The first optical fiber transmission component and the second optical fiber receiving component are respectively connected to the first optical fiber interface and the second optical fiber interface distributed on both sides of the flow channel of the microfluidic sorting chip; The third light source emitter emits light to the first optical fiber interface through the first optical fiber transmission component to stimulate the optical signal of the droplet to be measured; The second optical fiber receiving component is used to obtain the absorption light signal after the filtered light processing; Wherein, the second optical fiber receiving assembly includes an optical fiber receiver, a third plano-convex lens and a third filter; The third photomultiplier tube converts the absorbed light signal into an electrical signal.

6. The optical signal detection device according to any one of claims 3 to 5, characterized in that: The number of the first light source emitter, the second light source emitter and the third light source emitter is multiple; The wavelength band of the light emitted by each first light source emitter is not completely the same, the wavelength band of the light emitted by each second light source emitter is not completely the same, and the wavelength band of the light emitted by each third light source emitter is not completely the same; The wavelength band of the emitted light of the first light source emitter and the filtering parameters of the first filter match the fluorescence signal; the wavelength band of the emitted light of the second light source emitter and the filtering parameters of the second filter match the scattered light signal; the wavelength band of the emitted light of the third light source emitter and the filtering parameters of the third filter match the absorbed light signal.

7. The micro-droplet screening device according to claim 1, characterized in that: The signal processor is used to determine a branch channel that matches the intensity of the electrical signal of the droplet to be tested, and send the screening instruction to the electrical filter.

8. The micro-droplet screening device according to claim 7, characterized in that: The signal processor is used to send a movement instruction to the host computer when determining that the droplet to be tested is a positive droplet; The host computer controls the movement of the micro-droplet collecting device according to the movement instruction.

9. The micro-droplet screening device according to claim 8, characterized in that: The micro-droplet collecting device includes a plurality of collecting chambers; The host computer controls the movement of the micro-droplet collecting device when the number of droplets in a collection chamber reaches a preset number.

10. The micro-droplet screening device according to claim 1, wherein: The micro-droplet screening device further includes a liquid injection device, which includes a pressure pump, a syringe, and a liquid injection controller; The liquid injection device is electrically connected to the host computer, and the host computer controls the liquid injection device to inject the dispersed phase and the droplets to be tested into the microfluidic sorting chip; The syringe is installed in the pressure pump, and the injection controller controls the pressure pump to provide power to the syringe; An angle is set between the syringe and the horizontal plane.

11. The micro-droplet screening device according to claim 1, wherein: The host computer is used to visually display the optical signal when receiving the optical signal of the droplet to be measured; The host computer is also used to set parameters for the optical signal detection device, the signal processor and the electrical filter.

12. The micro-droplet screening device according to claim 7, wherein: The micro-droplet screening device further includes a light-shielding housing; The optical signal detection device is arranged in the light-shielding housing to block interference from ambient light.

13. A micro-droplet screening system, characterized in that: The micro-droplet screening system comprises a microfluidic sorting chip and the micro-droplet screening device according to any one of claims 1 to 12; the microfluidic sorting chip comprises an optical fiber channel, a sorting component, and at least two branch channels; The optical fiber channel is connected to the optical fiber interface for transmitting optical signals; The sorting component is used to sort the droplets to be tested into corresponding branch channels when receiving a deflection instruction.

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