Microfluidic chip and nucleic acid detection system

Abstract

A microfluidic chip and a nucleic acid detection system are provided. The microfluidic chip includes a substrate, which defines a rotation axis. The substrate includes a working part, which is arranged radially outside the rotation axis. The working part includes a sample loading tank, one or more filter tanks, and a reaction tank. The sample loading tank is used to accommodate samples and lysis reagents. At least some of the filter tanks include a delivery area and a sedimentation area. The sedimentation area of the same filter tank is arranged radially outside its delivery area, and the axial depth of the sedimentation area of the same filter tank is greater than the axial depth of its delivery area. The reaction tank is used to accommodate amplification reagents. The sample loading tank is connected to the reaction tank via the filter tank. The working part can rotate around the rotation axis, so that the sample can flow to the reaction tank through the filter tank under the action of centrifugal force, and the sample can be centrifuged in the filter tank. In this way, the microfluidic chip can have a better separation effect and a more compact structure.

Description

Technical Field

[0001] The present application relates to the field of microfluidics, and more specifically to a microfluidic chip and a nucleic acid detection system. Background Art

[0002] Chinese invention patent application CN110029052A discloses a microfluidic chip and analysis system. The sample loading chamber is connected to the PCR amplification chamber via a sample enrichment chamber. Due to the centrifugal field, cells, tissues, pathogens, and other components within the sample settle to the bottom of the sample enrichment chamber.

[0003] However, the aforementioned microfluidic chip is not suitable for viscous or highly concentrated samples. For viscous or highly concentrated samples such as sputum, the flocculent separated from the sample cannot be effectively retained at the bottom of the sample enrichment chamber, making it difficult for the sample enrichment chamber to fully separate the sample. Summary of the Invention

[0004] This application is made in view of the above-mentioned state of the prior art. The purpose of this application is to provide a microfluidic chip and a nucleic acid detection system, which can overcome at least one of the shortcomings described in the above-mentioned background technology.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions.

[0006] The present application provides the following microfluidic chip, comprising a base body, which defines a rotation axis, the base body comprising a working part, the working part being arranged radially outside the rotation axis, the working part comprising a loading slot, one or more filter slots and a reaction slot, the loading slot being used to accommodate samples and lysis reagents, at least some of the filter slots comprising a delivery area and a sedimentation area, the sedimentation area of the same filter slot being arranged radially outside its delivery area, the axial depth of the sedimentation area of the same filter slot being greater than the axial depth of its delivery area, the reaction slot being used to accommodate amplification reagents, the loading slot being connected to the reaction slot via the filter slot, wherein the working part can rotate around the rotation axis, so that the sample can flow to the reaction slot via the filter slot under the action of centrifugal force, and the sample can be centrifuged in the filter slot.

[0007] In an optional solution, a plurality of the filter tanks are arranged in series.

[0008] In another optional scheme, the working part also includes a conveying flow channel, and adjacent filter tanks are connected to each other via the conveying flow channel. At least a portion of the conveying flow channel is formed into a curved shape that arches radially inward, and one end of at least one conveying flow channel is connected to the radial inner part of one filter tank, and the other end is connected to the radial inner part of another filter tank.

[0009] In another optional scheme, the multiple filter tanks include a first filter tank and a second filter tank, the first filter tank includes a first sedimentation zone, the second filter tank includes a second sedimentation zone, the first filter tank is arranged on the upstream side of the second filter tank, the volume of the first filter tank is larger than the volume of the second filter tank, and / or the volume of the first sedimentation zone is larger than the volume of the second sedimentation zone.

[0010] In another optional solution, the working part is provided with a sample adding end and a venting end, the sample adding end and the venting end penetrate the base body along the axial direction of the base body, and the sample adding end is connected to the venting end via the sample adding groove.

[0011] In another optional scheme, it also includes a first seal and a second seal, the first seal is used to sealingly cover the axial end face of one side of the substrate to close the axial openings of the sample loading tank, the filter tank and the reaction tank, and the second seal is used to sealingly cover the axial end face of the other side of the substrate to close the axial openings of the sample loading end and the air permeable end.

[0012] In another optional scheme, the working part also includes a main input flow channel, a collecting flow channel and a plurality of auxiliary input flow channels, the main input flow channel extends radially along the base, the radial inner end of the main input flow channel is connected to the radial outer part of the sample loading slot, the radial outer end of the main input flow channel is connected to the radial inner part of one of the filter slots, the collecting flow channel extends circumferentially along the base, one circumferential end of the collecting flow channel is connected to the main input flow channel, the auxiliary input flow channel extends radially along the base, the plurality of auxiliary input flow channels are arranged circumferentially along the base, the main input flow channel is arranged on one circumferential side of the plurality of auxiliary input flow channels, the radial inner end of the auxiliary input flow channel is connected to the radial outer part of the sample loading slot, and the radial outer end of the auxiliary input flow channel is connected to the collecting flow channel.

[0013] In another optional solution, the working part further includes a buffer tank, the sample loading tank is connected to the reaction tank via the filter tank and the buffer tank in sequence, and / or the working part further includes a waste liquid tank, the sample loading tank is connected to the waste liquid tank via the filter tank.

[0014] In another optional solution, a plurality of the working parts are arranged along the circumference of the base body.

[0015] The present application also provides the following nucleic acid detection system, comprising: the above-mentioned microfluidic chip; a centrifugal module, which is used to drive the working part to rotate around the rotation axis; a temperature control module, which is used to adjust the temperature of the sample; and a control module, which is electrically connected to the centrifugal module and the temperature control module.

[0016] By adopting the above technical solution and setting up a sedimentation zone, larger particles in the sample can be firmly precipitated and maintained at the axial bottom of the sedimentation zone, and the filter tank can make full use of the axial space, so that the microfluidic chip can have a better separation effect and a more compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a substrate of a microfluidic chip of a nucleic acid detection system according to an embodiment of the present application is shown.

[0018] Figure 2 Shown Figure 1 A partial schematic diagram of the substrate in .

[0019] Description of Reference Numerals

[0020] 1 base; 11 working part;

[0021] G1 sample tank; G21 first filter tank; G22 second filter tank; G23 third filter tank; G24 fourth filter tank; G25 fifth filter tank; G3 buffer tank; G4 reaction tank; G5 waste liquid tank;

[0022] S11 first conveying area; S12 first settling area; S21 second conveying area; S22 second settling area; S31 third conveying area; S32 third settling area; S41 fourth conveying area; S42 fourth settling area;

[0023] P1 main input channel; P2 secondary input channel; P3 converging channel; P41 first delivery channel; P42 second delivery channel; P43 third delivery channel; P44 fourth delivery channel; P5 distribution channel; P6 buffer channel; P7 reaction channel; P8 waste liquid channel;

[0024] T1 sample addition end; T2 ventilation end;

[0025] A axial direction; C circumferential direction;

[0026] L is the axis of rotation. DETAILED DESCRIPTION

[0027] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0028] One embodiment of the present application provides a nucleic acid detection system, particularly a nucleic acid detection system suitable for sepsis sputum samples or alveolar lavage fluid samples.

[0029] The nucleic acid detection system may include a microfluidic chip, a centrifugation module, a temperature control module and a control module.

[0030] The microfluidic chip may include a substrate 1 , a first sealing member, and a second sealing member.

[0031] Reference Figure 1 The base 1 may include a plurality of working parts 11. Specifically, the base 1 may be disc-shaped, and the central axis of the base 1 may serve as the rotation axis L. The working parts 11 may be disposed radially outward from the rotation axis L, and the plurality of working parts 11 may be evenly arranged along the circumferential direction C. For example, in this embodiment, the base 1 may include four working parts 11, and the four working parts 11 may be evenly spaced and arranged along the circumferential direction C.

[0032] Reference Figure 2 The working part 11 may include a sample loading tank G1, multiple filter tanks, multiple buffer tanks G3, multiple reaction tanks G4, and a waste liquid tank G5. Specifically, the sample loading tank G1, the filter tank, the buffer tank G3, the reaction tank G4, and the waste liquid tank G5 may be arranged on one axial end surface of the base 1. The multiple filter tanks may include a first filter tank G21, a second filter tank G22, a third filter tank G23, a fourth filter tank G24, and a fifth filter tank G25 connected in series. The sample loading tank G1 may be arranged on the upstream side of the first filter tank G21, and the buffer tank G3 and the waste liquid tank G5 may be arranged on the downstream side of the fifth filter tank G25. The reaction tank G4 may be arranged on the downstream side of the buffer tank G3, and each buffer tank G3 may correspond to one reaction tank G4.

[0033] The sample loading groove G1 can be connected to the first filter groove G21 via the main input flow channel P1. Specifically, the axial bottom of the sample loading groove G1 can be provided with a sample loading end T1, and the sample loading end T1 can pass through the base body 1 along the axial direction A. The first filter groove G21 can include a first conveying area S11 and a first sedimentation area S12. The first conveying area S11 can be arranged radially inwardly of the first sedimentation area S12, and the axial depth of the first conveying area S11 can be less than the axial depth of the first sedimentation area S12. The first filter groove G21 can be arranged radially outwardly of the sample loading groove G1. The main input flow channel P1 can extend radially (including extending approximately radially). The radial inner end of the main input flow channel P1 can be connected to the radial outer portion of the sample loading groove G1, and the radial outer end of the main input flow channel P1 can be connected to the radial inner portion of the first conveying area S11.

[0034] The sample loading tank G1 can be connected to the main input channel P1 via a plurality of auxiliary input channels P2 and a collection channel P3. Specifically, the auxiliary input channels P2 can extend radially (including substantially radially), and the plurality of auxiliary input channels P2 can be arranged along the circumferential direction C. The length of the plurality of auxiliary input channels P2 can be from one side of the circumference ( Figure 2 the left side) to the other side ( Figure 2The converging flow channel P3 may extend along the circumferential direction C (including extending substantially along the circumferential direction C). The radially inner end of the auxiliary input flow channel P2 may be connected to the radially outer portion of the sample loading tank G1, and the radially outer end of the auxiliary input flow channel P2 may be connected to the converging flow channel P3. The main input flow channel P1 may be provided on one circumferential side of the plurality of auxiliary input flow channels P2 ( Figure 2 The left side of the channel P3 is collected at one circumferential end ( Figure 2 The left end of the secondary input channel P2 can be connected to the downstream end (or output end) of the primary input channel P1. A ventilation end T2 can be provided at the intersection of the secondary input channel P2 and the converging channel P3. The ventilation end T2 can pass through the substrate 1 along the axial direction A.

[0035] The first filter tank G21 can be connected to the second filter tank G22 via the first delivery channel P41. Specifically, the second filter tank G22 can include a second delivery area S21 and a second sedimentation area S22. The second delivery area S21 can be arranged radially inward of the second sedimentation area S22, and the axial depth of the second delivery area S21 can be less than the axial depth of the second sedimentation area S22. The second filter tank G22 can be arranged on one circumferential side of the first filter tank G21 ( Figure 2 The volume of the second filter tank G22 can be smaller than that of the first filter tank G21, and the volume of the second sedimentation area S22 can be smaller than that of the first sedimentation area S12. The first delivery channel P41 can be a semicircular shape that arches radially inward. One circumferential end of the first delivery channel P41 ( Figure 2 The left end in the middle) can be connected to the radial inner side of the second conveying area S21, and the other circumferential end of the first conveying flow channel P41 ( Figure 2 The right end in FIG) may be connected to the radially inner portion of the first conveying area S11.

[0036] The second filter tank G22 can be connected to the third filter tank G23 via the second delivery channel P42. Specifically, the third filter tank G23 can include a third delivery area S31 and a third sedimentation area S32. The third delivery area S31 can be arranged radially inward of the third sedimentation area S32, and the axial depth of the third delivery area S31 can be less than the axial depth of the third sedimentation area S32. The third filter tank G23 can be arranged on one circumferential side of the second filter tank G22 ( Figure 2 The volume of the third filter tank G23 can be smaller than that of the second filter tank G22, and the volume of the third sedimentation area S32 can be smaller than that of the second sedimentation area S22. The second delivery channel P42 can be a semicircular shape that arches radially inward. One circumferential end of the second delivery channel P42 ( Figure 2 The left end in the middle) can be connected to the radial inner side of the third conveying area S31, and the other circumferential end of the second conveying flow channel P42 ( Figure 2The right end in FIG20 may be connected to the radially inner portion of the second conveying area S21.

[0037] The third filter tank G23 can be connected to the fourth filter tank G24 via the third delivery channel P43. Specifically, the fourth filter tank G24 can be provided on one side of the circumference of the third filter tank G23 ( Figure 2 The volume of the fourth filter tank G24 can be smaller than that of the third filter tank G23. The third delivery channel P43 can be J-shaped. The vertical portion of the J-shape can extend radially (including substantially radially), and the curved portion of the J-shape can arch radially inward. The radially outer end of the third delivery channel P43 can be connected to the radially inner portion of the fourth filter tank G24, and the radially inner end of the third delivery channel P43 can be connected to the radially inner portion of the third delivery zone S31.

[0038] The fourth filter trough G24 can be connected to the fifth filter trough G25 via the fourth delivery channel P44. Specifically, the fifth filter trough G25 may include a fourth delivery area S41 and a fourth sedimentation area S42. The fourth delivery area S41 may be arranged radially inward of the fourth sedimentation area S42, and the axial depth of the fourth delivery area S41 may be smaller than the axial depth of the fourth sedimentation area S42. The fifth filter trough G25 may be arranged radially outward of the fourth filter trough G24. Preferably, the volume of the fifth filter trough G25 may be smaller than the volume of the fourth filter trough G24, and the volume of the fourth sedimentation area S42 may be smaller than the volume of the third sedimentation area S32. A portion of the fourth delivery channel P44 may be J-shaped. The vertical portion of the J-shape may extend radially (including extending approximately radially), and the curved portion of the J-shape may arch radially inward. The radially outer end of the fourth delivery channel P44 may be connected to a circumferential side portion ( Figure 2 The radially inner end of the fourth delivery flow path P44 may be connected to the radially inner portion of the fourth filter tank G24.

[0039] The fifth filter tank G25 can be connected to the plurality of buffer tanks G3 via the distribution channel P5 and the plurality of buffer channels P6. Specifically, the fifth filter tank G25 can be provided on one side of the circumference of the plurality of buffer tanks G3 ( Figure 2 The plurality of buffer grooves G3 may be arranged along the circumferential direction C. The distribution channel P5 may extend along the circumferential direction C (including substantially extending along the circumferential direction C), and one circumferential end of the distribution channel P5 ( Figure 2 The left end of the buffer flow channel P6 can be connected to the radial inner portion of the fourth delivery area S41. The buffer flow channel P6 can extend radially (including substantially radially extending), and multiple buffer flow channels P6 can be arranged along the circumferential direction C. One buffer flow channel P6 can correspond to one buffer groove G3. The radial inner end of the buffer flow channel P6 can be connected to the distribution flow channel P5, and the radial outer end of the buffer flow channel P6 can be connected to the radial inner portion of the buffer groove G3.

[0040] A plurality of buffer tanks G3 can be connected to a plurality of reaction tanks G4 via a plurality of reaction channels P7. Specifically, the buffer tank G3 can be arranged radially inwardly of the reaction tank G4, and the plurality of reaction tanks G4 can be arranged along the circumferential direction C. The reaction channel P7 can extend radially (including extending substantially radially), and the plurality of reaction channels P7 can be arranged along the circumferential direction C. One reaction channel P7 can correspond to one buffer tank G3 and one reaction tank G4. The radially inner end of the reaction channel P7 can be connected to the radially outer portion of the buffer tank G3, and the radially outer end of the reaction channel P7 can be connected to the radially inner portion of the reaction tank G4. The axial depth of the reaction tank G4 can be greater than the axial depth of the buffer tank G3.

[0041] The fifth filter tank G25 can be connected to the waste liquid tank G5 via the distribution channel P5 and the waste liquid channel P8. Specifically, the waste liquid tank G5 can be arranged on the other side of the circumference of the plurality of buffer tanks G3 and the plurality of reaction tanks G4 ( Figure 2 The waste liquid flow channel P8 may extend radially (including substantially radially). The radially inner end of the waste liquid flow channel P8 may be connected to the other circumferential end of the distribution flow channel P5 ( Figure 2 The radially outer end of the waste liquid flow channel P8 can be connected to the radially inner portion of the waste liquid tank G5.

[0042] A first seal and a second seal can be mounted on the substrate 1. Specifically, the first seal and the second seal can be films or sheets. The first seal can hermetically cover one axial end surface of the substrate 1 to seal the axial openings of the groove and flow channel. The second seal can hermetically cover the other axial end surface of the substrate 1 to seal the axial openings of the sample loading end T1 and the vent end T2. If the first seal and the second seal are sheets, they can be welded to the substrate 1.

[0043] The following describes how to use the nucleic acid detection system, which can generally include:

[0044] Placing an amplification reagent in the reaction tank G4, for example, the amplification reagent may include a fluorescent dye;

[0045] Installing the first sealing member on the base 1;

[0046] Place the sample and lysis reagent into the sample loading tank G1 via the sample loading port T1;

[0047] Installing the second sealing member on the base 1;

[0048] The sample and the lysis reagent are heated by the temperature control module, so that the cells in the sample are lysed under the action of the lysis reagent;

[0049] The microfluidic chip is driven to rotate around the rotation axis L by the centrifugal module, so that the nucleic acid in the sample flows into the reaction tank G4 under the action of centrifugal force; and

[0050] The nucleic acid and amplification reagent are heated by the temperature control module, so that the nucleic acid in the sample is amplified under the action of the amplification reagent.

[0051] The sample can be filtered through multiple filter tanks. Specifically, driven by centrifugal force, the lysed sample can flow from the sample loading tank G1 into the first filter tank G21. Within the first filter tank G21, larger particles in the sample can be distributed and settled in the first sedimentation zone S12, while smaller particles in the sample can be distributed in the first transport zone S11, allowing the larger particles to be at least partially separated from the sample. For example, in this embodiment, the larger particles can include flocculent matter in sputum, and the smaller particles can include nucleic acids dissolved in the solution. The sample leaving the first filter tank G21 can be further filtered in the second filter tank G22, the third filter tank G23, the fourth filter tank G24, and the fifth filter tank G25, in sequence, gradually increasing the concentration of nucleic acids in the sample. Here, for the fourth filter tank G24, which does not have a sedimentation zone, larger particles can be distributed and settled on the radially outer portion of the fourth filter tank G24, while smaller particles can be distributed on the radially inner portion of the fourth filter tank G24.

[0052] The waste tank G5 is used to accommodate excess sample. Specifically, when the buffer tanks G3 and reaction tanks G4 are full, excess sample can flow into the waste tank G5 via the distribution channel P5 and the waste channel P8. Furthermore, the gas within the waste tank G5 is compressed during centrifugation, thereby facilitating the flow of sample downstream.

[0053] The control module is used to control the centrifugal module and the temperature control module. Specifically, the control module can be electrically connected to the centrifugal module to adjust the centrifugal force and centrifugal time of the centrifugal module. For example, in the present embodiment, under the control of the control module, the centrifugal module can separate samples by differential centrifugation. The control module can be electrically connected to the temperature control module to adjust the heating temperature and heating time of the temperature control module. For example, in the present embodiment, the lysis temperature and the amplification temperature can be different. In addition, under the control of the control module, the centrifugal module and the temperature control module can automatically work according to the program, so that the nucleic acid detection system can have a high degree of automation.

[0054] The microfluidic chip of this embodiment has at least the following advantages.

[0055] (i) The microfluidic chip exhibits excellent separation performance. Specifically, by ensuring that the depth of the sedimentation zone is greater than that of the transport zone, larger particles can be firmly deposited and retained at the axial bottom of the sedimentation zone, making it less likely for larger particles to flow downstream with smaller particles. Consequently, larger particles can be effectively separated from the sample. Furthermore, by providing multiple filter tanks in series, the sample can be filtered multiple times, further enhancing the separation performance.

[0056] (ii) The microfluidic chip has a relatively compact structure. Specifically, by making the depth of the sedimentation zone greater than the depth of the delivery zone, the filter tank can fully utilize the axial space. Given a certain volume, the opening of the filter tank can have a smaller area, resulting in a relatively compact layout of the tanks and flow channels of the microfluidic chip.

[0057] (iii) The microfluidic chip has a high flow efficiency. Specifically, by making the curved portion of the transport channel convex radially inward, the channel's extension direction has a radial component, allowing the sample to be driven by centrifugal force within the channel, thereby smoothly passing through the channel. Furthermore, by making the volume of the multiple filter tanks decrease in the direction of sample flow, the sample can be fully filtered while flowing through the multiple filter tanks at a faster rate.

[0058] (iv) The microfluidic chip is less susceptible to sample clogging. Specifically, by providing the secondary input channel P2 and the converging channel P3, samples can enter the primary input channel P1 in a more dispersed manner, thereby preventing clogging of the primary input channel P1 by samples. In some possible scenarios, even if the input end of the primary input channel P1 is clogged by sample, the sample can flow into the primary input channel P1 via the secondary input channel P2 and then enter the first filter tank G21 via the output end of the primary input channel P1.

[0059] (v) The microfluidic chip is easy to use. Specifically, by providing a vent port T2, gas within the sample loading tank G1 can be discharged from the sample loading tank G1 through the vent port T2, so that the air pressure within the sample loading tank G1 can be maintained balanced during the sample loading process, thereby facilitating the addition of samples to the sample loading tank G1.

[0060] (vi) The microfluidic chip has the function of filtering bubbles. Specifically, by providing a buffer tank G3, bubbles carried by the sample can be retained in the buffer tank G3, so that the bubbles do not occupy the space of the reaction tank G4, thereby ensuring that the sample can fully flow into the reaction tank G4.

[0061] It should be understood that the above embodiments are merely exemplary and are not intended to limit the present application. Those skilled in the art may make various modifications and changes to the above embodiments based on the teachings of the present application without departing from the scope of the present application.

[0062] It should be understood that the number of filtration slots can be adjusted according to the sample. For example, for a sample that is easy to filter, the microfluidic chip may have only one filtration slot.

[0063] It should be understood that the temperature adjustment module is not limited to having a heating function, and may have a cooling function, for example.

Claims

1. A microfluidic chip, characterized in that: The invention comprises a base (1) which defines a rotation axis (L), the base (1) comprising a working portion (11), the working portion (11) being arranged radially outside the rotation axis (L), the working portion (11) comprising a sample loading slot (G1), one or more filter slots and a reaction slot (G4), the sample loading slot (G1) being used to accommodate a sample and a lysis reagent, at least part of the filter slots comprising a delivery area and a precipitation area, the precipitation area of the same filter slot being arranged radially outside its delivery area, the axial depth of the precipitation area of the same filter slot being greater than the axial depth of its delivery area, the reaction slot (G4) being used to accommodate an amplification reagent, the sample loading slot (G1) being connected to the reaction slot (G4) via the filter slot, wherein The working part (11) is capable of rotating around the rotation axis (L), so that the sample can flow through the filter tank to the reaction tank (G4) under the action of centrifugal force, and the sample can be centrifugally separated in the filter tank. A plurality of said filter tanks are arranged in series, The working part (11) further includes a conveying flow channel, and adjacent filter tanks are connected to each other via the conveying flow channel. At least a portion of the conveying flow channel is formed into a curved shape that arches radially inward. One end of at least one conveying flow channel is connected to the radial inner side of one filter tank, and the other end is connected to the radial inner side of another filter tank. The working portion (11) is provided with a sample adding end (T1) and a venting end (T2), wherein the sample adding end (T1) and the venting end (T2) penetrate the base body (1) along the axial direction (A) of the base body (1), and the sample adding end (T1) is connected to the venting end (T2) via the sample adding groove (G1). The working part (11) further includes a main input flow channel (P1), a converging flow channel (P3) and a plurality of auxiliary input flow channels (P2). The main input flow channel (P1) extends radially along the base (1), the radial inner end of the main input flow channel (P1) is connected to the radial outer side of the sample addition tank (G1), and the radial outer end of the main input flow channel (P1) is connected to the radial inner side of one of the filter tanks. The converging flow channel (P3) extends along the circumferential direction (C) of the base body (1), and one circumferential end of the converging flow channel (P3) is connected to the main input flow channel (P1). The auxiliary input flow channel (P2) extends radially along the base (1), and the multiple auxiliary input flow channels (P2) are arranged along the circumferential direction (C) of the base (1). The main input flow channel (P1) is arranged on one circumferential side of the multiple auxiliary input flow channels (P2), the radial inner end of the auxiliary input flow channel (P2) is connected to the radial outer side of the sample loading groove (G1), and the radial outer end of the auxiliary input flow channel (P2) is connected to the converging flow channel (P3).

2. The microfluidic chip according to claim 1, wherein The plurality of filter tanks include a first filter tank and a second filter tank, the first filter tank includes a first sedimentation area, the second filter tank includes a second sedimentation area, and the first filter tank is arranged on the upstream side of the second filter tank. The volume of the first filter tank is greater than the volume of the second filter tank, and / or The volume of the first precipitation zone is greater than the volume of the second precipitation zone.

3. The microfluidic chip according to claim 1, wherein The invention also includes a first sealing member and a second sealing member, wherein the first sealing member is used to sealingly cover the end face of one axial side of the substrate (1) to close the axial openings of the sample addition tank (G1), the filter tank and the reaction tank (G4), and the second sealing member is used to sealingly cover the end face of the other axial side of the substrate (1) to close the axial openings of the sample addition end (T1) and the air permeable end (T2).

4. The microfluidic chip according to claim 1 or 2, characterized in that: The working part (11) further includes a buffer tank (G3), the sample adding tank (G1) is connected to the reaction tank (G4) via the filter tank and the buffer tank (G3) in sequence, and / or The working part (11) further includes a waste liquid tank (G5), and the sample adding tank (G1) is connected to the waste liquid tank (G5) via the filter tank.

5. The microfluidic chip according to claim 1 or 2, characterized in that: The plurality of working parts (11) are arranged along the circumferential direction (C) of the base body (1).

6. A nucleic acid detection system, characterized in that: include: The microfluidic chip according to any one of claims 1 to 5; a centrifugal module for driving the working part (11) to rotate around the rotation axis (L); a temperature adjustment module, configured to adjust the temperature of the sample; and A control module is electrically connected to the centrifugal module and the temperature adjustment module.

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