Magnetic pipetting device and method capable of adjusting number of channels

Abstract

The invention relates to the technical field of precise pipetting equipment in laboratories, and provides a magnetic pipetting device and method capable of adjusting the number of channels, aiming at solving the problems that the number of channels is fixed and switching is tedious in the conventional pipetting equipment, and the sealing property depends on manual inspection. The main gun body recognizes the number of channels connected with the gun head in the current state through the controller to drive the independent piston driving assemblies at the corresponding positions to complete pipetting, and when the gun head is replaced, the quick release button is pressed down to enable the connected gun head to fall off from the main gun body. Pipetting of the gun heads with different channel numbers can be completed by connecting the gun head used next time to the main gun body, the experiment efficiency can be remarkably improved, and the multi-channel pipette is suitable for high-throughput screening, PCR split charging and other scenes where the channel number needs to be frequently switched and has the comprehensive advantages of being convenient to operate, high in compatibility and high in reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of laboratory precision pipetting equipment, and in particular to a magnetic pipetting device and method with adjustable number of channels. Background Art

[0002] In biomedical, pharmaceutical research and development, and molecular biology experiments, pipetting equipment is one of the most commonly used tools in laboratories for accurately transferring trace amounts of liquid (such as DNA samples, reagents, cell culture media, etc.). Traditional automated pipetting equipment is mainly divided into single-channel pipettes and multi-channel pipettes (such as 8-channel, 12-channel), but the existing technology has the following significant problems: fixed number of channels and poor flexibility. The number of channels of existing pipettes is fixed at the time of factory production (such as 8 channels or 12 channels). If the experiment requires switching to different numbers of channels (such as switching from single-channel to multi-channel), the entire pipetting equipment must be replaced, which is cumbersome to operate and increases costs. Low modularity and low replacement efficiency. Some high-end equipment supports modular design, but it relies on mechanical buckles or threaded connections, with complex disassembly and assembly steps, and is prone to reduced sealing performance due to wear, affecting pipetting accuracy. Sealing depends on manual inspection, which is prone to errors. The sealing performance of traditional pipettes is usually ensured by O-rings or rubber gaskets, but they are prone to aging after long-term use, resulting in liquid leakage or cross-contamination, and laboratory personnel often cannot monitor the sealing state in real time. Poor adaptability to high-viscosity liquids. Existing pipettes are mostly optimized for aqueous liquids. When transferring high-viscosity liquids (such as blood, glycerol), it is easy to generate bubbles or residues, affecting the accuracy of experiments. Insufficient automation integration. Existing pipetting equipment is difficult to seamlessly connect with automated workstations, lacking intelligent recognition and adaptive control functions, which limits the efficiency of high-throughput experiments.

[0003] Improvement attempts in the prior art: Patent CN108525096B proposed a sealing structure for a multi-channel pipette, but still requires manual replacement of modules and does not solve the problem of flexible switching of the number of channels. The commercial product Opentrons OT-2 uses an automated pipetting platform, but has limited modularity and high costs, making it difficult to popularize. Market demand and technical gap. Laboratories urgently need a pipetting equipment that can quickly switch the number of channels, has reliable sealing and is compatible with automation to improve experimental efficiency and reduce human errors. Summary of the Invention

[0004] In view of the deficiencies of the existing technology, the present invention proposes a magnetic pipetting device and method with adjustable number of channels. Through pipette tips with different numbers of channels, intelligent seal detection, and highly compatible structures, the present invention realizes the rapid switching of the number of channels of the pipetting device, significantly improves experimental efficiency, and real-time monitors the sealing state through a pressure sensor to reduce the contamination risk of high-value samples, especially suitable for scenarios such as high-throughput screening and PCR aliquoting that require frequent switching of the number of channels, and has the comprehensive advantages of convenient operation, strong compatibility, and high reliability.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A magnetic adsorption pipetting device with adjustable number of channels, comprising a main gun body and a plurality of gun heads with different numbers of channels. The gun heads are connected to the lower end of the main gun body through a magnetic adsorption base arranged at the bottom of the main gun body; an identification unit for identifying the number of channels of the currently connected gun head and a plurality of independent piston drive assemblies are arranged in the main gun body. A partition plate is arranged between adjacent independent piston drive assemblies. The signal for identifying the number of channels of the installed gun head by the identification unit is connected to the first signal input end of the controller. The independent piston drive assemblies are driven by the control signal output by the controller. The controller drives a plurality of independent piston drive assemblies corresponding to the gun head according to the received signal of the number of channels; the main gun body is also provided with a quick release button for replacing the gun head and a pressure sensor for detecting the sealing performance. The signal of the quick release button is connected to the second input end of the controller; the pressure sensor is arranged in the pump cavity of the main gun body, and the signal of the pressure sensor is connected to the third input end of the controller.

[0007] Further, the magnetic adsorption base includes an electromagnet array located at the bottom of the main gun body and matching the maximum number of channels of the gun head, and a guide pin for positioning the gun head and the main gun body. The guide pins are located on both sides of the electromagnet array and are asymmetrically distributed.

[0008] Further, a positioning plate is arranged on the surface of the gun head in contact with the main gun body. All liquid suction channels are arranged in the positioning plate, and a plurality of positioning holes matching the guide pins are arranged on the surface of the positioning plate.

[0009] Further, a liquid-repellent coating is arranged on the inner wall of the liquid suction channel of the gun head, and an elastic sealing ring is arranged at the port of the liquid suction channel at one end of the positioning plate.

[0010] Further, the identification unit includes an RFID tag for representing each gun head with a different number of channels and an RFID reader for reading the RFID tag. The RFID tag is placed inside the gun head, and the RFID reader is placed inside the main gun body. The signal output end of the RFID reader is connected to the fourth signal input end of the controller. The RFID reader identifies the number of channels corresponding to the currently connected gun head according to the read RFID tag.

[0011] A pipetting method using a magnetic adsorption pipetting device with adjustable number of channels, based on the above magnetic adsorption pipetting device with adjustable number of channels, the main gun body drives a plurality of independent piston drive assemblies at corresponding positions to complete pipetting by identifying the number of channels of the currently connected gun head through the controller. When replacing the gun head, press the quick release button to make the connected gun head fall off from the main gun body, and connect the gun head to be used next time to the main gun body to complete pipetting with gun heads of different numbers of channels. The specific steps are as follows:

[0012] Step 1. After the power of the magnetic suction pipette device with adjustable channel number is turned on, the controller determines the sealing of the magnetic suction pipette device according to the signal of the pressure sensor. If the pressure change value exceeds the set threshold range, it is determined that the sealing is unqualified, and the sealing alarm is turned on; if the pressure change value is within the set threshold range, it is determined that the sealing is qualified, the controller energizes the electromagnet array, and the gun head is connected to the main gun body using the electromagnet array and the guide pin;

[0013] Step 2. The RFID reader reads the RFID tag of the gun head to identify the channel number corresponding to the currently connected gun head, and the controller drives the independent piston drive assembly of the corresponding channel according to the connected gun head to perform liquid suction or discharge operation;

[0014] Step 3. When you need to replace the gun tip, press the quick release button to remove the currently connected gun tip. Connect the required gun tip to the main gun body and repeat step 2 to complete channel identification and pipetting operations until all operations are completed and the gun tip is removed.

[0015] In summary, the present invention has significant advantages over the prior art:

[0016] The present invention adopts a magnetic structure between the gun tip and the main gun body to achieve rapid replacement of the gun tip, shortening the replacement time to less than 2 seconds, and improving the efficiency by more than 7 times; the double-stage seal cooperates with real-time monitoring to reduce the risk of leakage to less than 0.1%; the automatic identification function ensures that the pipetting accuracy reaches ±0.5%; it supports free switching of 1 / 6 / 12 channels, and can be adapted to a variety of experimental consumables such as 96-well plates and PCR tubes. The structure of the present invention in which a main gun body is used in conjunction with multiple gun tips with different numbers of channels is suitable for experimental scenarios such as high-throughput screening and PCR packaging that require frequent switching of the number of channels. It has the comprehensive advantages of convenient operation, strong compatibility and high reliability. The present invention does not require a main gun body to be configured for each gun tip with a certain number of channels, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figures 1 to 3 They are schematic diagrams of the overall structure of the present invention and the structures of gun tips with different numbers of channels.

[0018] Figure 4 It is a structural schematic diagram of the main gun body connection surface of the present invention.

[0019] Figure 5 It is a bottom-up structural comparison diagram of the gun tips with different numbers of channels of the present invention.

[0020] Figure 6 It is a cross-sectional view of the magnetic connection between the gun head and the main gun body.

[0021] In the figure, 1 is the main gun body, 2 is the independent piston drive unit, 3 is the 12-channel gun head, 4 is the 6-channel gun head, 5 is the single-channel gun head, 6 is the magnetic adsorption base, 7 is the electromagnet array, 8 is the guide pin, 9 is the positioning plate, 10 is the positioning hole, 11 is the elastic sealing ring, and 12 is the spiral microgroove. Detailed implementation mode

[0022] The present invention will be further described in detail below with reference to the accompanying drawings.

[0023] It should be noted that for the convenience of description, the description of directions in the following text is consistent with the directions of the accompanying drawings themselves, but does not limit the structure of the present invention.

[0024] As Figures 1 to 4 shown, the present invention discloses a magnetic adsorption type pipetting device with adjustable number of channels, including a main gun body 1 and a plurality of gun heads with different numbers of channels. The gun heads are connected to the lower end of the main gun body 1 through a magnetic adsorption base 6 arranged at the bottom of the main gun body 1. The magnetic adsorption base 6 includes an electromagnet array 7 located at the bottom of the main gun body 1 and matching the maximum number of channels of the gun head, and a guide pin 8 for positioning the gun head and the main gun body 1. The guide pin 8 is located on both sides of the electromagnet array 7 and is asymmetrically distributed; an identification unit for identifying the number of channels of the currently connected gun head and a plurality of independent piston drive assemblies 2 are arranged in the main gun body 1. A partition plate is arranged between adjacent independent piston drive assemblies. The signal of the number of channels of the installed gun head identified by the identification unit is connected to the first signal input end of the controller. The independent piston drive assemblies are driven by the control signal output by the controller. The controller drives a plurality of independent piston drive assemblies corresponding to the gun head according to the received signal of the number of channels; a positioning plate 9 is arranged on the surface of the gun head in contact with the main gun body 1. All liquid suction channels are placed in the positioning plate 9. A plurality of positioning holes 10 matching the guide pin 8 are arranged on the plate surface of the positioning plate 9. A hydrophobic coating is arranged on the inner wall of the liquid suction channel of the gun head, and an elastic sealing ring 11 is arranged at the port of the liquid suction channel at one end of the positioning plate 9.

[0025] The main gun body 1 is also provided with a quick release button for replacing the gun head and a pressure sensor for detecting the sealing performance. The signal of the quick release button is connected to the second input end of the controller; the pressure sensor is arranged in the pump cavity of the main gun body 1, and the signal of the pressure sensor is connected to the third input end of the controller.

[0026] The identification unit includes an RFID tag for representing each gun head with a different number of channels and an RFID reader for reading the RFID tag. The RFID tag is placed in the gun head, and the RFID reader is placed in the main gun body 1. The signal output end of the RFID reader is connected to the fourth signal input end of the controller. The RFID reader identifies the number of channels corresponding to the currently connected gun head according to the read RFID tag.

[0027] The present invention also discloses a pipetting method using a magnetic pipetting device with adjustable number of channels. Based on the above-mentioned magnetic pipetting device with adjustable number of channels, the main gun body 1 drives a number of independent piston drive assemblies 2 at corresponding positions to complete pipetting through the controller identifying the number of channels of the connected pipette tip in the current state. When replacing the pipette tip, press the quick release button to make the connected pipette tip fall off from the main gun body, and connect the pipette tip to be used next time to the main gun body 1 to complete pipetting with pipette tips of different numbers of channels. The specific steps are as follows:

[0028] Step 1. After the power of the magnetic pipetting device with adjustable number of channels is turned on, the controller judges the sealing performance of the magnetic pipetting device according to the signal of the pressure sensor. If the pressure change value exceeds the set threshold range, it is considered that the sealing performance is unqualified and the sealing alarm is turned on; if the pressure change value is within the set threshold range, it is considered that the sealing performance is qualified, and the controller energizes the electromagnet array 7, and the pipette tip is connected to the main gun body 1 by using the electromagnet array 7 and the guide pin 8. The threshold range can be adjusted according to the requirements of actual operation and the properties of the liquid.

[0029] During the operation, the pressure sensor is always in the working state, monitors the pressure change of the closed cavity, and combines with the movement of the independent piston drive assembly 2 to judge whether there is leakage in the magnetic pipetting device. If there is leakage, the sealing alarm is turned on. The sealing detection is as follows:

[0030] i. The controller controls the independent piston drive assembly 2 to retract the piston to generate negative pressure in the cavity formed by the pipette tip and the main gun body 1.

[0031] ii. The piston stops moving, maintains the closed state of the cavity, and the pressure sensor continuously collects the pressure value.

[0032] iii. Calculate the pressure decay rate. If the rate exceeds the set threshold, it is determined that the seal fails and the sealing alarm is turned on.

[0033] Step 2. The RFID reader reads the RFID tag of the pipette tip to identify the number of channels corresponding to the connected pipette tip in the current state. The signal of the RFID reader is transmitted to the controller. The controller determines the number of channels of the connected pipette tip according to the received signal, and drives the independent piston drive assembly 2 of the corresponding channel to perform liquid aspiration or discharge operations.

[0034] Step 3. When it is necessary to replace the pipette tip, press the quick release button. The signal of the quick release button is transmitted to the controller. The controller outputs a cut-off signal to the electromagnet, and the electromagnet is powered off. The currently connected pipette tip falls off. Connect the required pipette tip to the main gun body 1, and repeat Step 2 to complete the channel identification and pipetting operations until the pipette tip is removed after all operations are completed.

[0035] In this embodiment, the electromagnet adopts a combined structure of a neodymium iron boron permanent magnet with a diameter of 8 mm and an electromagnetic coil, which can generate an adsorption magnetic field of 0.5 T. The guide pins 8 are arranged in an asymmetric manner, with a distance of 14.5 mm between three of the pins and 15.5 mm between the other three, ensuring that the gun head can only be installed in the correct direction when connecting. As Figure 5 clearly shows the positioning plate structure of the gun head, including the asymmetric arrangement of eccentric positioning holes and the sealing ring installation slots.

[0036] In this embodiment, the gun head has three configurations of 1-channel, 6-channel, and 12-channel. The interfaces of the 6-channel gun head are linearly arranged at a standard spacing of 9.00 ± 0.01 mm. The 12-channel gun head adopts a double-row staggered arrangement, with a row spacing of 4.50 ± 0.01 mm. The positioning plate 9 at the bottom of the gun head has a thickness of 2.0 mm, a surface roughness Ra ≤ 0.2 μm. The positioning plate 9 is machined with positioning holes 10 that cooperate with the guide pins 8. The positioning holes 10 are eccentric positioning holes, and the hole diameter tolerance is controlled within ±0.005 mm.

[0037] The replacement and connection of the gun head adopt magnetic fast connection. During installation, the gun head approaches the main gun body 1 at a 15° inclination angle. The guide pins 8 are first inserted into the positioning holes 10 for rough positioning. Subsequently, the electromagnetic coil is energized for 0.5 seconds to generate an additional magnetic field to make the gun head fit tightly with the main gun body 1. The elastic sealing ring 11 is compressed by 0.5 mm to generate a contact pressure of 0.35 ± 0.05 MPa; a PVDF piezoelectric film sensor can be added to the gun head, with a detection range of -100 kPa to +100 kPa and a measurement accuracy of ±0.5%; a secondary seal can also be added. The secondary seal is to machine spiral micro-grooves 12 on the inner wall of the gun head, with a pitch of 0.5 mm and a depth of 0.1 mm, which can effectively prevent liquid from climbing by capillary action.

[0038] The identification unit reads the information of the RFID tag of the gun head connected in the current state. When a 6-channel gun head is detected, the controller drives the independent piston assemblies 2 of the corresponding channels to activate the middle 6 groups of independent piston drive assemblies 2. The adjacent units are completely isolated by titanium alloy separator plates. When a 12-channel gun head is connected, all 12 groups of independent piston drive assemblies 2 are enabled and operate in a time-division multiplexing manner.

[0039] The gun head of the present invention realizes fast, accurate, and reliable gun head switching through a mechanical and magnetic composite structure. The switching process of different channel number modules can be completed within 2 seconds. When replacing, press the quick release button, and the electromagnetic coil is reversely energized for 0.1 second to cancel the magnetic field of the permanent magnet. The ejector pin arranged on the contact surface between the main gun body and the gun head extends by 1.5 mm to provide an initial separation force, and the gun head automatically falls off under the action of gravity. The magnetic pipetting device re-identifies the channel number of the newly installed gun head and performs liquid aspiration or discharge operations.

[0040] The magnetic pipetting device is optimized for fluid dispensing with different numbers of channels. In the 6-channel mode, parallel pipetting is adopted, and each channel is independently controlled; in the 12-channel mode, an alternating working method is used, and the odd channels and even channels operate at different times to ensure power stability. The CAN bus inside the main gun body 1 synchronizes the states of each channel at a period of 1 ms. For liquids with different properties, the present invention provides adaptive pipetting control: when dealing with high-viscosity liquids, the piston speed can be dynamically adjusted within the range of 0.1-5 mm / s, and vibration drainage with a frequency of 10 Hz and an amplitude of 0.2 mm is used; in the standard mode, a constant flow rate of 10 μL / s is maintained.

[0041] The variable-channel function shows significant advantages in practical applications. Taking the example of adding samples to a 96-well plate, the 6-channel mode is suitable for row-wise sample addition, the 12-channel mode is suitable for column-wise sample addition, and the 1-channel mode is convenient for precise liquid replenishment of individual wells. Tests show that the volume error during channel switching is controlled within ±0.5%, fully meeting the requirements of high-precision experiments.

[0042] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A magnetic suction pipetting device with adjustable channel number, characterized in that: The invention comprises a main gun body (1) and a plurality of gun heads with different numbers of channels, wherein the gun heads are connected to the lower end of the main gun body (1) via a magnetic adsorption base (6) arranged at the bottom of the main gun body (1); an identification unit for identifying the number of channels of the currently connected gun head and a plurality of independent piston drive assemblies (2) are arranged in the main gun body (1), and an isolation plate is arranged between adjacent independent piston drive assemblies. A signal of the number of channels of the installed gun head identified by the identification unit is connected to a first signal input terminal of a controller, and the independent piston drive assemblies are driven by control signals output by the controller, and the controller drives the plurality of independent piston drive assemblies corresponding to the gun heads according to the received signal of the number of channels; The main gun body (1) is also provided with a quick release button for replacing the gun head and a pressure sensor for detecting the sealing performance, and the signal of the quick release button is connected to the second input terminal of the controller; the pressure sensor is arranged in the pump chamber of the main gun body (1), and the signal of the pressure sensor is connected to the third input terminal of the controller.

2. The magnetic suction pipetting device with adjustable channel number according to claim 1, characterized in that: The magnetic adsorption base (6) comprises an electromagnet array (7) located at the bottom of the main gun body (1) and matching the maximum number of channels of the gun head, and guide pins (8) used to achieve positioning of the gun head and the main gun body (1), wherein the guide pins (8) are located on both sides of the electromagnet array (7) and are distributed in an asymmetrical manner.

3. The magnetic suction pipetting device with adjustable channel number according to claim 1, characterized in that: A positioning plate (9) is arranged on the side of the gun head that is in contact with the main gun body (1), all the liquid suction channels are placed in the positioning plate (9), and a plurality of positioning holes (10) matching with the guide pins (8) are arranged on the surface of the positioning plate (9).

4. The magnetic suction pipetting device with adjustable channel number according to claim 3, characterized in that: A liquid-repellent coating is provided on the inner wall of the liquid suction channel of the gun head, and an elastic sealing ring (11) is provided at the port of the liquid suction channel located at one end of the positioning plate (9).

5. The magnetic suction pipetting device with adjustable channel number according to claim 1, characterized in that: The identification unit comprises an RFID tag for indicating each gun head with different channel numbers and an RFID reader for reading the RFID tag. The RFID tag is placed in the gun head, and the RFID reader is placed in the main gun body (1). The signal output end of the RFID reader is connected to the fourth signal input end of the controller. The RFID reader identifies the channel number corresponding to the connected gun head in the current state according to the read RFID tag.

6. A liquid transfer method using a magnetic liquid transfer device with adjustable channel number, based on the magnetic liquid transfer device with adjustable channel number according to any one of claims 1 to 5, characterized in that: The main gun body (1) recognizes the number of channels of the gun tip connected in the current state through the controller to drive a number of independent piston drive components (2) at corresponding positions to complete the pipetting. When the gun tip is replaced, the quick release button is pressed to make the connected gun tip fall off from the main gun body, and the gun tip to be used next is connected to the main gun body (1) to complete the pipetting of gun tips with different channel numbers. The specific steps are as follows: Step 1. After the power of the magnetic suction type liquid transfer device with adjustable channel number is turned on, the controller determines the sealing performance of the magnetic suction type liquid transfer device according to the signal of the pressure sensor. If the pressure change value exceeds the set threshold range, it is determined that the sealing performance is unqualified, and the sealing alarm is turned on; if the pressure change value is within the set threshold range, it is determined that the sealing performance is qualified, and the controller energizes the electromagnet array (7), and the gun head is connected to the main gun body (1) by using the electromagnet array (7) and the guide pin (8); Step 2. The RFID reader reads the RFID tag of the gun tip to identify the channel number corresponding to the currently connected gun tip, and the controller drives the independent piston drive assembly (2) of the corresponding channel according to the connected gun tip to perform liquid suction or discharge operation; Step 3. When the gun tip needs to be replaced, press the quick release button to remove the currently connected gun tip, connect the required gun tip to the main gun body (1), and repeat step 2 to complete channel identification and pipetting operations until all operations are completed and the gun tip is removed.

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