Sample introduction structure for preventing multi-channel cross contamination and micro-fluidic chip

Abstract

The utility model discloses a sample introduction structure for preventing cross contamination of multiple channels and a micro-fluidic chip, the sample introduction structure comprises a sample introduction groove, a uniform mixing groove, a flow guide flow channel, a separate injection flow channel and a reaction cavity which are sequentially arranged on a disc capable of centrifugally rotating, and the sample introduction groove is arranged in an area close to the circle center of the disc; the flow guide runner is arranged in an area far away from the circle center of the disc; the sample adding groove is communicated with the uniform mixing groove, the uniform mixing groove is communicated with the flow guide flow channel, a plurality of separated injection flow channels and reaction cavities are sequentially arranged on the outer side of the flow guide flow channel and in the area far away from the circle center of the disc, the separated injection flow channels are located at the top end of the flow guide flow channel, and the flow guide flow channel is connected with the corresponding reaction cavities through the separated injection flow channels; and the depth of the flow guide runner is greater than that of the separate injection runner. According to the sampling structure capable of preventing cross contamination of the multiple channels, a certain height difference is set between the flow guide flow channel and the separate injection flow channel, so that the risk of cross contamination is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of biological detection, in particular to a sampling structure for preventing multi-channel cross contamination and a microfluidic chip comprising the structure. Background Art

[0002] Microfluidics technology is currently a hot area of ​​development, recognized for its enormous potential and broad application prospects in biomedical research. Microfluidic chips integrate the fundamental operational elements of biological, chemical, and medical analytical processes, including sample preparation, reaction, separation, and detection, onto a tiny chip, automating the entire analytical process. They feature controllable fluid flow, minimal sample and reagent consumption, and rapid analysis speeds. They can analyze hundreds of samples simultaneously in minutes or even less, and can perform sample pretreatment and analysis online.

[0003] Application number CN202410600888.6 discloses a portable blood cell examination method based on microfluidic imaging technology, which includes the following steps: Step 1, microfluidic chip design; design a first microfluidic chip and a second microfluidic chip, the first microfluidic chip has 4 sample addition holes, and the blood sample is dripped into the 4 sample addition holes and flows into the detection area respectively. The second microfluidic chip has 1 sample addition hole. After the blood sample is dripped into the sample addition hole, it automatically flows into 4 detection areas, namely the hemoglobin detection area, the white blood cell detection area, the red blood cell detection area and the platelet detection area; all detection areas are pre-embedded with reagents, and the pre-embedding method includes at least embedding, freeze-drying and drying. Step 2, blood sample processing, the mixed blood sample is added to the sample addition hole of the microfluidic chip, and the blood sample fills the detection area through capillary effect and siphon effect. When the blood sample reaches the detection area of ​​the microfluidic chip, it mixes and reacts with the pre-embedded reagent so that the blood cell solution can meet the imaging conditions.

[0004] The integrated detection of microfluidic chips allows a sample to be tested for multiple items simultaneously. Therefore, multiple reaction chambers are often designed. However, reaction reagents are usually pre-installed in the reaction chambers. During sample addition or transportation, there is a risk of reaction reagents in the reaction chambers overflowing, affecting the accuracy of the results. Utility Model Content

[0005] In view of the above-mentioned defects of the prior art, the utility model provides an injection structure that prevents multi-channel cross-contamination. The depth of the diversion channel is cleverly set to be greater than the depth of the injection channel, so that the liquid in the diversion channel is placed at the bottom. Even if the reagent in a certain reaction chamber overflows into the diversion channel, due to the certain height difference between the liquid in the diversion channel and the injection channel, the contaminated liquid in the diversion channel cannot enter the adjacent reaction chamber again through the injection channel; for this reason, the utility model also provides a microfluidic chip including the injection structure.

[0006] The first aspect of the present invention provides a sampling structure for preventing multi-channel cross-contamination, including a sampling slot, a mixing slot, a guide channel, a dispensing channel and a reaction chamber arranged in sequence on a centrifugally rotatable disc, wherein the sampling slot is arranged in an area close to the center of the disc, and the guide channel is arranged in an area away from the center of the disc; the sampling slot is connected to the mixing slot, and is used to add the sample to be tested in the sampling slot to the mixing slot for mixing; the mixing slot is connected to the guide channel, and is used to add the sample to be tested in the mixing slot to the guide channel; a plurality of dispensing channels and reaction chambers are sequentially arranged on the outside of the guide channel and away from the center of the disc, the dispensing channel is located at the top of the guide channel, and the guide channel is connected to the corresponding reaction chamber through a plurality of dispensing channels; the depth of the guide channel is greater than the depth of the dispensing channel.

[0007] The sample to be tested is added to the sample loading tank. Under the centrifugal force of the centrifugal rotation of the disc, the sample to be tested in the sample loading tank enters the mixing tank, and then enters the diversion channel through the mixing tank, and then enters each reaction chamber through each injection channel, completing the entire injection process.

[0008] Because the depth of the diversion channel is greater than the depth of the dispensing channel, under the action of centrifugal force, the sample to be tested located in the diversion channel will enter the dispensing channel. When the injection process is completed, the disk no longer rotates. When the liquid in a certain reaction chamber overflows into the corresponding dispensing channel and then enters the diversion channel, due to a certain height difference between the liquid levels of the diversion channel and the dispensing channel, the liquid level of the diversion channel is lower than the liquid level of the dispensing channel. At this time, the liquid in the diversion channel cannot flow back to the dispensing channel, and thus cannot cause contamination to other adjacent reaction chambers, thereby reducing the possibility of cross contamination.

[0009] As a preferred embodiment, the depth difference between the diversion channel and the injection channel is ≥3500 μm.

[0010] As a preferred embodiment, the guide channel, reaction chamber and injection channel are all made of hydrophobic materials.

[0011] By using hydrophobic materials for the diversion channel, reaction chamber and injection channel, the liquid in the diversion channel, reaction chamber and injection channel will not automatically overflow due to capillary phenomenon, reducing the risk of reaction liquid overflow and avoiding cross contamination.

[0012] As a more preferred embodiment, the hydrophobic material is PMMA.

[0013] Polymethyl methacrylate, referred to as PMMA, is a high molecular polymer with excellent hydrophobic properties.

[0014] As a preferred embodiment, the reaction chambers are distributed on arcs of the same radius of the disk.

[0015] By arranging multiple reaction chambers on the arc of the same radius of the disk, simultaneous detection of multiple items can be achieved.

[0016] As a preferred embodiment, reaction reagents are preset in the reaction chamber.

[0017] As a more preferred embodiment, the reaction reagent is a liquid reagent, a freeze-dried powder or a freeze-dried strain.

[0018] As a preferred embodiment, the bottom end of the reaction chamber is conical.

[0019] The bottom end of the reaction chamber is configured to be conical, thereby reducing the risk of overflow of the reaction liquid in the reaction chamber.

[0020] As a preferred embodiment, a breathable membrane is provided at the top of the reaction chamber.

[0021] After adding the pre-set reagent into the reaction chamber, a layer of breathable membrane is set on the top of the reaction chamber to reduce the risk of the pre-set reagent in the reaction chamber overflowing.

[0022] A second aspect of the present invention provides a microfluidic chip, characterized in that it includes the above-mentioned sampling structure for preventing multi-channel cross-contamination.

[0023] The above-mentioned sample injection structure is used in a microfluidic chip to reduce the possibility of multi-channel cross-contamination and improve the accuracy of detection using the microfluidic chip.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention has an injection structure that prevents multi-channel cross-contamination. A certain height difference is set between the guide channel and the injection channel. During injection, the sample to be tested in the guide channel is added to the injection channel and the reaction chamber by centrifugal action. When the reaction chamber is in a static state, the height difference prevents the liquid in the guide channel from flowing back into the injection channel, thereby reducing the risk of cross-contamination.

[0026] (2) The present invention has an injection structure that prevents multi-channel cross-contamination. Since the guide channel, reaction chamber and injection channel are made of hydrophobic materials, the liquid in the guide channel, reaction chamber and injection channel will not automatically overflow due to capillary phenomena, thereby reducing the risk of reaction liquid overflow in the reaction chamber and avoiding cross-contamination.

[0027] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a sampling structure for preventing multi-channel cross contamination according to the present invention.

[0029] Figure 2 The utility model is a diagram showing the positional relationship between the flow guide channel, the reaction chamber and the injection channel in the sampling structure for preventing multi-channel cross contamination.

[0030] Figure 3 This is an installation diagram of a disc in a sampling structure for preventing multi-channel cross contamination in the utility model.

[0031] Figure 4 This is a schematic diagram of the test results of the sampling structure for preventing multi-channel cross contamination of the utility model, wherein Figure 4 a corresponds to the test time 0h, Figure 4 b corresponds to the test for 24 hours.

[0032] Among them: 1- sample loading tank, 2- mixing tank, 3- diversion channel, 4- injection channel, 5- reaction chamber, 6- disk, 7- carrier plate. DETAILED DESCRIPTION

[0033] In order to make the technical means, creative features, objectives and effects of the utility model easier to understand, the utility model is further described below with reference to specific figures. However, the utility model is not limited to the following implementation cases.

[0034] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in this utility model without affecting the effects and purposes that can be achieved by the present utility model.

[0035] Microfluidic chips are a detection method based on microfluidics technology. They use tiny channels to carry liquids into the chip to mix, react, separate, or detect substances. Microfluidic chips are an efficient, sensitive, and rapid detection method with a wide range of applications in drug discovery, genetic testing, bioanalysis, environmental monitoring, and other fields.

[0036] Microfluidic chips achieve simultaneous testing of multiple projects by setting up multiple reaction chambers. Reaction reagents are usually pre-installed in the reaction chamber. During the sample addition or transportation process, there is a risk of the reaction reagents in the reaction chamber overflowing and entering the adjacent reaction chamber, affecting the accuracy of the results.

[0037] In order to solve the above problems, the inventors of the present application tried to add samples by centrifugal rotation instead of the traditional method of adding samples by capillary phenomenon and siphon effect, and set the depth of the diversion channel 3 to be greater than the depth of the dispensing channel 4, so that the dispensing channel 4 is located at the top of the diversion channel 3. During sampling, under the action of centrifugal force, the sample to be tested located in the diversion channel 3 enters the dispensing channel 4 and the reaction chamber 5; and when the sampling process is completed, the centrifugal rotation stops, and the reaction chamber 5 is in a static state, the reaction liquid in the reaction chamber 5 may overflow and enter the dispensing channel 4, and then the reaction liquid in the dispensing channel 4 enters the diversion channel 3. However, due to the certain depth of the diversion channel 3, there is a certain height difference between the liquid levels in the diversion channel 3 and the dispensing channel 4, and the liquid in the diversion channel 3 cannot flow back to the dispensing channel 4 at all.

[0038] In order to reduce the risk of overflow of the reaction liquid in the reaction chamber 5, the diversion channel 3, the injection channel 4 and the reaction chamber 5 are made of hydrophobic material. The liquid in the diversion channel 3, the reaction chamber 5 and the injection channel 4 will not automatically overflow due to capillary phenomena, thereby reducing the risk of cross contamination.

[0039] Example 1

[0040] like Figure 1 、 2 3. A sampling structure for preventing multi-channel cross-contamination includes a sample loading slot 1, a mixing slot 2, a flow channel 3, a dispensing channel 4, and a reaction chamber 5, sequentially arranged on a centrifugally rotatable disk 6. The disk 6 is a sector-shaped disk that is clamped to a matching circular carrier disk 7, which drives the disk 6 to rotate at high speed. The sample adding slot 1 is arranged in an area close to the center of the disk 6, and the diversion channel 3 is arranged in an area away from the center of the disk 6; the sample adding slot 1 is connected to the mixing slot 2, and is used to add the sample to be tested in the sample adding slot 1 to the mixing slot 2 for mixing; the mixing slot 2 is connected to the diversion channel 3, and is used to add the sample to be tested in the mixing slot 2 to the diversion channel 3; a plurality of dispensing channels 4 and reaction chambers 5 are sequentially arranged on the outside of the diversion channel 3 and away from the center of the disk 6, and the dispensing channel 4 is located at the top of the diversion channel 3, and the diversion channel 3 is connected to the corresponding reaction chamber 5 through a plurality of dispensing channels 4; the depth of the diversion channel 3 is greater than the depth of the dispensing channel 4.

[0041] The depth difference between the diversion channel 3 and the dispensing channel 4 is ≥ 3500 μm. This depth difference creates a height difference between the liquid levels in the diversion channel 3 and the dispensing channel 4. The liquid level in the diversion channel 3 is lower than that in the dispensing channel 4. When the disk is stationary, the liquid in the diversion channel 3 cannot flow back into the dispensing channel 4, thereby preventing it from contaminating other adjacent reaction chambers 5.

[0042] The guide channel 3, the reaction chamber 5 and the injection channel 4 are all made of a hydrophobic material, and the hydrophobic material is PMMA.

[0043] By using hydrophobic materials for the diversion channel 3, the reaction chamber 5 and the dispensing channel 4, the liquid in the diversion channel 3, the reaction chamber 5 and the dispensing channel 4 will not automatically overflow due to capillary phenomena, thereby reducing the risk of reaction liquid overflow and avoiding cross contamination.

[0044] The reaction chambers 5 are distributed on the circular arcs of the same radius of the disk 6. The samples to be tested enter the various injection channels 4 and the reaction chambers 5 in sequence through the guide channels 3, which is used for simultaneous testing of multiple items.

[0045] The reaction chamber 5 is pre-set with a reaction reagent, which can be a liquid reagent, freeze-dried powder or freeze-dried strain. The sample to be tested enters the reaction chamber 5 through the diversion channel 3 and reacts with the reaction reagent to perform the corresponding test.

[0046] The bottom end of the reaction chamber 5 is tapered, which reduces the risk of the reaction liquid in the reaction chamber 5 overflowing.

[0047] A breathable membrane is provided on the top of the reaction chamber 5. After the pre-set reagent is added to the reaction chamber 5, a layer of breathable membrane is placed on the top of the reaction chamber 5 to reduce the risk of the pre-set reagent in the reaction chamber 5 overflowing.

[0048] The method of using the injection structure to prevent multi-channel cross contamination is as follows:

[0049] S1. Preset reaction reagents in the reaction chamber 5. The reaction reagents can be liquid reagents, freeze-dried powders or freeze-dried strains.

[0050] S2. Add the sample to be tested into the sample adding tank 1. Under the centrifugal force of the centrifugal rotation of the disc, the sample in the sample adding tank 1 enters the mixing tank 2, and enters the guide channel 3 through the mixing tank 2, and then enters each reaction chamber 5 through each injection channel 4, completing the entire injection process.

[0051] Example 2

[0052] A microfluidic chip comprises the above-mentioned sampling structure for preventing multi-channel cross contamination.

[0053] The above-mentioned sample injection structure is used in a microfluidic chip to reduce the possibility of multi-channel cross-contamination and improve the accuracy of detection using the microfluidic chip.

[0054] Example 3 Performance Testing

[0055] Methylene blue solution and pure water are used as pre-set reagents, and pure water is added to the reaction chamber 5 between the two reaction chambers 5 added with the methylene blue solution, that is, the pre-set reagents are added to the reaction chamber 5 in such a manner that one reaction chamber 5 is filled with methylene blue solution and the adjacent reaction chamber 5 is filled with pure water.

[0056] The preset reagents are added into the reaction chamber 5 in an alternating manner of methylene blue solution and pure water, and then a transparent film is attached.

[0057] Add the sample to be tested into the sample adding tank 1. Under the action of centrifugal force, the sample to be tested in the sample adding tank 1 enters the mixing tank 2 and the guide channel 3 in turn, and then enters each reaction chamber 5 through each injection channel 4 to react with the preset reagent. Because of the centrifugal force during the injection process, the liquid in the guide channel 3 enters the injection channel 4 and the reaction chamber 5 in turn, while the liquid in the reaction chamber 5 cannot flow back into the injection channel 4 and the guide channel 3. At this time, the result is as follows Figure 4 As shown in a.

[0058] After standing for 24 hours, the reaction chamber 5 of pure water did not turn blue or be contaminated. Figure 4 As shown in b.

[0059] Therefore, due to the certain height difference between the diversion channel 3 and the injection channel 4, after the centrifugation is completed, the reaction chamber 5 is in a static state. Even if the reaction liquid in the reaction chamber 5 overflows and enters the injection channel 4 and then enters the diversion channel 3, due to the existence of the height difference, the liquid in the diversion channel 3 cannot flow back into the injection channel 4 again, and will not cause pollution to the adjacent reaction chamber 5.

[0060] In addition, since the diversion channel 3, the reaction chamber 5 and the dispensing channel 4 are all made of hydrophobic materials, the liquid in the diversion channel 3, the reaction chamber 5 and the dispensing channel 4 will not automatically overflow due to capillary phenomena, which reduces the risk of overflow of the reaction liquid for the reaction chamber 5; similarly, the liquid in the diversion channel 3 will not automatically flow to the dispensing channel 4, and the liquid in the dispensing channel 4 will not automatically flow to the diversion channel 3, thereby avoiding cross contamination.

[0061] The above describes in detail the preferred embodiments of the present invention. It should be understood that a person skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solution that can be derived by a person skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology shall be within the scope of protection defined by the claims.

Claims

1. A sampling structure for preventing multi-channel cross contamination, comprising a sample loading slot, a mixing slot, a flow guide channel, a dispensing channel, and a reaction chamber sequentially arranged on a centrifugally rotatable disc, characterized in that: The sample loading slot is arranged in an area close to the center of the disk, and the flow guide channel is arranged in an area away from the center of the disk; The sample adding tank is connected to the mixing tank and is used to add the sample to be tested in the sample adding tank to the mixing tank for mixing; The mixing tank is connected to the diversion channel and is used to add the sample to be tested in the mixing tank to the diversion channel; A plurality of diversion channels and reaction chambers are sequentially arranged on the outside of the diversion channel and in an area away from the center of the disk. The diversion channel is located at the top of the diversion channel, and the diversion channel is connected to the corresponding reaction chamber through a plurality of diversion channels; the depth of the diversion channel is greater than the depth of the diversion channel.

2. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: The depth difference between the diversion flow channel and the injection flow channel is ≥3500 μm.

3. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: The diversion flow channel, reaction chamber and injection flow channel are all made of hydrophobic materials.

4. The sampling structure for preventing multi-channel cross contamination according to claim 3, characterized in that: The hydrophobic material is PMMA.

5. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: The reaction chambers are distributed on arcs of the same radius of the disk.

6. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: Reaction reagents are preset in the reaction chamber.

7. The sampling structure for preventing multi-channel cross contamination according to claim 6, characterized in that: The reaction reagent is a liquid reagent, a freeze-dried powder or a freeze-dried strain.

8. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: The bottom end of the reaction chamber is conical.

9. The sampling structure for preventing multi-channel cross contamination according to claim 1, characterized in that: A breathable membrane is provided on the top of the reaction chamber.

10. A microfluidic chip, characterized in that: The invention comprises the sampling structure for preventing multi-channel cross contamination according to any one of claims 1 to 9.

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