CN210506297U

CN210506297U - Micro flow channel chip and micro flow channel structure

Info

Publication number: CN210506297U
Application number: CN201920350538.3U
Authority: CN
Inventors: 董久源; 蔡松锜
Original assignee: Laifu Kede Biotechnology Co Ltd
Current assignee: Dong Jiuyuan
Priority date: 2019-03-20
Filing date: 2019-03-20
Publication date: 2020-05-12
Anticipated expiration: 2029-03-20

Abstract

The utility model relates to a miniflow channel chip and miniflow channel structure, the miniflow channel chip includes the miniflow channel structure, just the miniflow channel structure includes: a detection section having a first end for receiving the microfluidic sample and a second end for discharging the microfluidic sample after inspection or processing; a slow flow section having a third end and a fourth end, wherein the third end is connected to the second end and is configured to receive the assayed or processed microfluidic sample, and the fourth end is configured to discharge the assayed or processed microfluidic sample to a recovery zone; and a slow flow main channel which is positioned between the third end and the fourth end and is used for reducing the speed of the third end receiving the tested or processed microfluidic sample.

Description

Micro flow channel chip and micro flow channel structure

Technical Field

The present invention relates to a micro flow channel chip and a micro flow channel structure, which increase the capture rate of biological substances, and more particularly, to a micro flow channel chip and a micro flow channel structure having a curved flow channel.

Background

Cancer, which is derived from a disease in which a gene is mutated to cause abnormal proliferation of cells, has long been a serious medical problem. Cells that are shed from the primary site of a tumor and enter the blood circulation system through the mutation, either early or late in the definition of cancer, are called Circulating Tumor Cells (CTCs), which are considered to be a necessary prerequisite for the development of distant metastasis of the tumor, which is an organ-localized disease in most cases, but eventually is almost propagated to distant organs through the blood stream to form metastases, and this distant metastasis is a major cause of death of tumor patients. The accurate count of CTC and the molecular marker have important index functions for the judgment and curative effect evaluation of tumor patients after healing.

The severity of the tumor itself is related to the dynamic change in the number of CTCs, and thus can be used for early in vitro diagnosis, rapid evaluation of drug selection, personalized treatment, and the like. However, CTCs are rare cells that are difficult to collect, with only one CTC per 109 blood cells, making detection and isolation of CTCs technically difficult. Therefore, a centralized collection method must be used to efficiently detect and isolate CTCs.

An example of a current focused collection method is the use of highly over-expressed Cell surface biomarkers, such as Epithelial Cell Adhesion molecules (EpCAM), with high specificity and sensitivity to CTCs. Nagrath et al (Nature 2007,450:1235-9) developed anti-EpCAM antibody-based coated microfluidic chips for the detection and collection of CTCs. However, the drawback of the above technique is the low detection rate of pure CTCs, which is due to the non-specific binding of blood cells to anti-EpCAM antibodies.

Despite the advances in technologies for detecting and isolating CTCs, there remains a need for more specific and efficient methods for detecting, purifying and releasing CTCs and other biological substances for further breeding and characterization.

Therefore, the applicant has made various experiments and studies to overcome the above-mentioned shortcomings in the prior art, and finally, the micro flow channel chip and the micro flow channel structure of the present invention are invented to improve the above-mentioned shortcomings in the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a novel microfluid system contains the miniflow channel chip and is arranged in the miniflow channel chip and can snatch the pearl body of circulation tumor cell to separate circulation tumor cell from blood cell. In addition, the utility model discloses a microchannel chip can increase the fluid resistance in the microchannel including crooked unhurried current district section to slow down the flow velocity of microfluid sample in the microchannel structure, in order to increase the rate of snatching of the pearl body.

The utility model discloses a microfluid system principle is that the characteristic of utilizing circulation tumor cell surface antigen does with the antibody of planting on the pearl surface and snatchs, this pearl body structure leads to the biggest area of contact in the unit volume, secondly the fluid resistance of miniflow way structure and curved type structure cause the vortex to produce, lead to circulation tumor cell rotation or roll and increase the contact chance with the pearl body and strengthen the effect of snatching, and by the special design of miniflow way structure, reduce the nonspecific combination of blood cell and anti EpCAM antibody.

An aspect of the utility model provides a micro flow channel chip, include: a substrate; the body is provided with a first surface and a second surface, wherein the second surface is closely covered on the substrate; and a micro-channel structure embedded on the second surface, so that the micro-channel structure forms a micro-channel between the body and the substrate, and a blood sample flows in the micro-channel structure, wherein the micro-channel structure comprises: the slow flow section is provided with a slow flow main flow channel which is of a repeated bending structure (labyrinth) and is used for reducing the flow speed of the blood sample in the micro flow channel structure.

Another aspect of the present invention provides a structural body for making a microfluidic sample flow through the microchannel structure and be examined or treated, wherein the structural body comprises: a detection section having a first end and a second end, wherein the first end is used for receiving the microfluidic sample, and the second end is used for discharging the microfluidic sample after being inspected or processed; a buffering section having a third end and a fourth end, wherein the third end is connected to the second end and is configured to receive the assayed or processed microfluidic sample, and the fourth end is configured to discharge the assayed or processed microfluidic sample to a recovery area; and a slow flow main channel which is positioned between the third end and the fourth end and is used for reducing the speed of the third end receiving the tested or processed microfluidic sample.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1(A) is a schematic top view of a microchannel chip according to the present invention;

FIG. 1(B) is a schematic top view of another embodiment of the micro flow channel chip of the present invention;

FIG. 2(A) is a schematic longitudinal sectional view taken along A-A' in FIG. 1 (A);

FIG. 2(B) is a schematic longitudinal sectional view taken along A-A' of FIG. 1 (B);

FIG. 3(A) is a schematic view of beads disposed in a detection section of a micro flow channel chip according to the present invention;

FIG. 3(B) is a schematic view of another embodiment of the micro flow channel chip of the present invention showing beads disposed in the detection section;

FIG. 4 is a schematic view of a micro flow channel structure according to another embodiment of the present invention;

FIG. 5 is a graph of the recovery efficiency and detection limit of a microfluidics-free system;

FIG. 6 is a graph showing the recovery efficiency and detection limit of the microchannel chip according to the present invention;

FIGS. 7(A) -7(C) are images of the results of separation of blood samples by the microchannel chip of the present invention.

Detailed Description

The following description will be made for each embodiment of the micro flow channel chip and the micro flow channel structure having a meandering flow channel, with reference to the accompanying drawings, but the actual configuration and the method to be carried out do not necessarily completely conform to the description, and those skilled in the art can make various changes and modifications without departing from the actual spirit and scope of the present invention.

The embodiment of the utility model provides a separate circulating tumor cells from blood. The micro flow channel chip is internally provided with a plurality of transparent beads, when the beads capture the circulating tumor cells, the circulating tumor cells can be separated from the blood and positioned in the detection section, and the residual normal blood cells can flow out of the outlet and flow into the waste liquid storage tank. For capturing and isolating circulating tumor cells in the blood, the bead surface is preferably coated with an antibody to Epithelial cell adhesion Molecule (EpCAM).

Please refer to fig. 1(a), 1(B), 2(a), 2(B), 3(a) and 3(B), which are schematic top views and schematic longitudinal cross-sectional views along a-a' of the micro flow channel chip of the present invention. The micro flow channel chip 10 of the present invention includes beads 40, a substrate 100, a body 200, and a micro flow channel structure 300. The body 200 has a first surface 210 and a second surface 220 opposite to the first surface 210, the micro channel structure 300 is embedded in the second surface 220 of the body 200, and the second surface 220 is covered on the substrate 100 in a sealing manner, so that the micro channel structure 300 forms a micro channel between the body 200 and the substrate 100.

The beads of the present invention are especially large beads with a particle size of 100-. The bead surface coated reactive material comprises (1) a releasable composition that releases or removes non-specific blood cells and other blood components (such as proteins); (2) capturing the bioactive components of the biological substance; or (3) a linking molecule linked to the releasable component and the biologically active component.

The micro flow channel structure 300 of the present invention comprises a blood sample inlet 310, an expansion section 320, a resistance increasing section 330, a detection section 340, a slow flow section 350 and a blood sample outlet 360 in sequence from the inlet to the outlet.

The blood sample inlet 310 of the present invention extends from the first surface 210 to the second surface 220 of the body 200 for the blood sample to enter the flow channel. The blood sample inlet 310 may be a circular hole or a polygonal hole, preferably a circular hole. The diameter of the blood sample inlet 310 of the present invention is between 0.8-1.2mm, and can accommodate an injector with 18-21G needles (about 0.7-0.9 mm).

The utility model discloses expand the one end and be connected with blood sample entry 310 of district 320, the other end is connected with resistance-increasing district section 330. The aperture of the expansion section 320 may be circular or polygonal, preferably square. The utility model discloses expand the width of district section 320 and be between 0.8-1.5mm, and the degree of depth is 1 mm.

The resistance-increasing section 330 of the present invention has one end connected to the second end 322 of the expanding section 320 and the other end connected to the detecting section 340. The aperture of the resistance-increasing section 330 may be circular or polygonal, preferably square. The width of the resistance increasing section 330 of the utility model is between 250 and 500 μm, and the depth is 1 mm.

The detecting section 340 of the present invention includes a first end 341 and a second end 343, wherein the first end 341 is connected to the resistance increasing section 330, the second end 343 is connected to the slow flow section 350, and the beads 40 capable of adsorbing the circulating tumor cells in the blood are disposed in the detecting section 340 (as shown in fig. 3(a) and 3 (B)). The aperture of the detection section 340 may be circular or polygonal, preferably square. In the embodiment of the present invention, the aperture of the detecting section 340 is square. The depth of the detection section 340 is 20-50 μm added to the particle size of the beads 40, so the depth of the detection section 340 is between 120 μm and 250 μm. The width of the detecting section 340 is such that the beads 40 can pass through it, and is between 250 μm and 1.5 mm.

The utility model discloses unhurried current district section 350 includes first end 351, unhurried current main flow channel 352 and second end 353, and the first end 351 of unhurried current district section 350 is connected with the second end 343 of listening district section 340, and unhurried current district section 350's second end 353 is connected with blood sample export 360, and unhurried current main flow channel 352 is located between first end 351 and the second end 353. The slow flow main channel 352 may be a straight channel (not shown) or a repeating channel (labyrinth) (as shown in fig. 1 a and 3 a), and is preferably a repeating channel. The aperture of the sluggish section 350 may be circular or polygonal, preferably square. In the embodiment of the present invention, the aperture of the slow flow section 350 is square. The width of the first end 351 of the slow flow section 350 and the slow flow main channel 352 may be equal to or less than the width of the second end 343 of the detection section 340, and the depth of the first end 351 of the slow flow section 350 and the slow flow main channel 352 is less than the depth of the detection section 340. To accelerate the blood sample passing through the slow flow main flow channel 352 out of the micro flow channel structure 300, the aperture of the second end 353 of the slow flow section 350 is larger than the aperture of the slow flow main flow channel 352 (as shown in fig. 1(a), 2(a), and 3 (a)). In another embodiment, the aperture of the second end 353 of the slow flow section 350 may also be equal to the aperture of the slow flow main channel 352 (as shown in fig. 1(B), 2(B) and 3 (B)). The width of the slow flow section 350 of the present invention is between 150 and 250 μm, and the depth of the first end 351 of the slow flow section 350 and the slow flow main channel 352 is between 50-100 μm.

In order to stabilize the flow speed of the blood sample in the micro flow channel chip 10, the utility model discloses special design: (1) the depth of the slow flow section 350 is smaller than the depth of the second end 343 of the detection section 340 (as shown in fig. 2(a) and 2 (B)); and (2) the structure of the slow flow main channel 352 is a repeated bending structure (as shown in fig. 1(a) and 1 (B)). The special design can increase the fluid resistance in the micro flow channel chip 10, so that the flow rate of the blood sample in the micro flow channel chip 10 is reduced, the blood sample is prevented from uneven flow rate due to the intensified pressure or unstable force applied when the blood sample is injected from the blood sample inlet 310, the same flow rate can be ensured when the circulating tumor cells pass through the detection main region 342, and the probability of the circulating tumor cells being adsorbed to the beads 40 is increased.

The slower the flow rate of the blood sample, the higher the adsorption efficiency of the beads 40. Table 1 shows the effect of the depth of the slow flow section 350 on the adsorption of biological substances in a blood sample by the beads 40.

TABLE 1

As can be seen from Table 1, when the depth of the slow flow section 350 is 100 μm, the adsorption efficiency of the beads 40 is 10 to 20%, and when the depth of the slow flow section 350 is 50 μm, the adsorption efficiency of the beads 40 is 88%. Therefore, the smaller the depth of the slow flow section, the smaller the cross-sectional area of the slow flow section 350, and further the flow speed and flow rate of the blood sample in the micro flow channel structure 300 are reduced, so that the adsorption efficiency of the beads 40 is higher.

The utility model discloses blood sample outlet 360's one end is connected with the second end 353 of slow flow section 350, and the other end extends to first surface 210 from second surface 220 of body 200. Blood cells not captured by the beads 40 will flow through the blood sample outlet 360 to a waste recovery zone (not shown). The blood sample outlet 360 may be a round or square hole, preferably a round hole, and has a diameter of between 0.8-1.2 mm.

Table 2 below shows a preferred embodiment of the bead 40 particle size and the pore diameter of each section in the micro flow channel structure 300.

TABLE 2

The material of the substrate 100 of the present invention may be acryl (PMMA), polyethylene terephthalate (PET), Polycarbonate (PC), Polydimethylsiloxane (PDMS), silica gel, rubber, plastic or glass. The material of the body 200 may be acryl (PMMA), polyethylene terephthalate (PET), Polycarbonate (PC), Polydimethylsiloxane (PDMS), silicone, rubber, or plastic. When selecting the materials of the substrate 100 and the body 200, the material characteristics between the substrate 100 and the body 200 must be considered. In the embodiment of the present invention, the substrate 100 is glass, and the body 200 is polydimethylsiloxane.

The beads 40 of the present invention are made of transparent plastic or transparent resin. The microfluidic sample may be a body fluid or a bacterial fluid, and the body fluid may include blood, cerebrospinal fluid, various digestive fluids, semen, saliva, sweat, urine, vaginal secretion, or a solution containing a biological substance. Biological substances include CTCs, CTC circulating stem cells (e.g., tumor stem cells, liver stem cells, and bone marrow stem cells), fetal cells, bacteria, viruses, epithelial cells, endothelial cells, or other biological substances. Therefore, the substance applied to the surface of the beads differs for different objects to be grasped.

The present invention also provides another embodiment of a micro flow channel structure 50, as shown in fig. 4. The micro channel structure 50 carries beads 60 and has a structure body 500, the structure body 500 sequentially includes a micro fluid sample inlet 510, a resistance increasing section 520, a detecting section 530, a slow flow section 540 and a micro fluid sample outlet 550 from the inlet to the outlet, wherein the beads 60 are located in the detecting section 530, and the slow flow section 540 has a slow flow main channel 541 which is a repeatedly bent structure to reduce the speed of the micro fluid sample in the micro channel structure 50. When the microfluidic sample enters from the microfluidic sample inlet 510, the microfluidic sample can directly enter the detection section 530 through the resistance increasing section 520, capture the biological substances in the microfluidic sample by the beads 60 in the detection section 530, so as to perform the inspection or treatment of the microfluidic sample, then enter the slow flow section 540, and finally flow out of the microfluidic channel structure 50 from the microfluidic sample outlet 550.

The utility model discloses a preparation method of microchannel chip utilizes the 3D printer to print the master model earlier, and the master model is that photocuring resin washes through 95% alcohol, and UV photocuring 2 minutes back is washed with alcohol once more and is placed the oven and toasts 10 minutes. Food-grade material PDMS liquid is poured into the master mold in proportion, and after 50 minutes and 80 degrees of curing, the master mold is bonded with the glass substrate by an oxygen plasma machine.

Examples of the experiments

Research on grabbing circulating tumor cells by large beads after cultured circulating tumor cell beads are placed in physiological experiment water buffer solution

1. Recovery efficiency and detection limit of large beads (200 μm diameter) in microfluid-free systems

Respectively putting 10, 1000 and 10 ten thousand circulating tumor cells and the beads and 1mL of physiological saline buffer solution (simulated blood environment) into a centrifuge tube, fully and uniformly mixing the circulating tumor cells and the beads in the physiological saline buffer solution, and observing the grasping efficiency of the beads. According to fig. 5, the experimental results show that in the experimental group with only 10 ten thousand circulating tumor cells, 1.5% of the cells (about 1500) are captured by the beads, whereas in the experimental group with 10 and 1000 circulating tumor cells, the beads do not capture any circulating tumor cells, which represents a blood environment of less than 1000 circulating tumor cells, and the beads cannot capture any circulating tumor cells.

2. The recovery efficiency and detection limit of the micro flow channel chip of the present invention are large beads (200 μm in diameter)

Respectively with 10, 50, 100, 500 and 1000 circulating tumor cells and 1mL physiological saline buffer solution mixture, the liquid sample after will mixing flows through the utility model discloses a bead body in the microchannel chip to observe the efficiency of snatching of bead body. According to fig. 6, the experimental result shows to utilize the utility model discloses a micro-channel chip contains more than 50 circulating tumor cells in the liquid sample just can snatch, compares in the result that no micro-fluidic system handled (need 10 ten thousand cells could be snatched, as shown in fig. 6), and the detection limit obviously reduces 2000 times, and utilizes the utility model discloses a micro-channel chip's recovery efficiency is on average higher than 5%, and is about 3 times higher than no micro-fluidic system's recovery efficiency.

When the number of circulating tumor cells in the blood of a human body is about 50 or more per 10mL on average, the risk of cancer in the human body is high. Therefore, the experiment proves that only the large beads (200 μm in diameter) can not distinguish the risk of cancer, but the large beads can be matched with the micro flow channel chip of the utility model can effectively and accurately capture the circulating tumor cells in the blood, and can more quickly judge whether the cancer is suffered.

Refer to FIGS. 7(A) -7(C), which show the results of separation by the micro flow channel chip of the present invention after the blood specimen of a cancer patient is actually stained. FIG. 7(A) is a box where circulating tumor cells are captured on the hyaline beads, FIG. 7(B) is an arrow where leukocytes are erroneously captured by the hyaline beads, and FIG. 7(C) is a box where all captured cell positions are obtained after synthesizing FIG. 7(A) and FIG. 7 (B). This experiment proves that the second stage cancer patient is in the present invention, the result shows that about 13 circulating tumor cells are captured, and only 3 leukocyte cells are captured (because the number of leukocyte cells in 1mL blood of human body is about 106-107, according to strict definition, 106 leukocyte cells are used to estimate, i.e. one million leukocyte cells capture only 3 leukocyte cells, which is far lower than the current capture rate of Cellsearch instrument through FDA proof (about 3000-4000 leukocyte cells) in the micro flow channel chip). In addition, the experimental result only needs 30 minutes from the acquisition of the blood sample to the display of the image result, and the time is greatly shortened compared with the conventional method that the pretreatment and the separation of the circulating tumor cells to the reading of the image result take 6 to 9 hours. Therefore, utilize the utility model discloses a micro-channel chip can effectually grab micro-circulating tumor cell in the blood, has very low mistake rate of grabbing, and only needs 30 minutes can obtain the result, so the utility model discloses a micro-channel chip can regard as the preliminary detection to have the quick sieve biochip of cancer.

Other embodiments

1. A micro flow channel chip comprising: a substrate; the body is provided with a first surface and a second surface, wherein the second surface is closely covered on the substrate; and a micro-channel structure embedded on the second surface, so that the micro-channel structure forms a micro-channel between the body and the substrate, and a blood sample flows in the micro-channel structure, wherein the micro-channel structure comprises: the slow flow section is provided with a slow flow main flow channel which is of a repeated bending structure (labyrinth) and is used for reducing the flow speed of the blood sample in the micro flow channel structure.

2. The micro flow channel chip of embodiment 1, further comprising a detection section, and the slow flow section further comprises a first end and a second end, wherein the first end of the slow flow section is connected to the detection section, wherein the detection section is used for testing or processing the blood sample and discharging the tested or processed blood sample, and the first end of the slow flow section is used for receiving the tested or processed blood sample.

3. The micro flow channel chip of embodiment 2, wherein the detection section has a first depth and the slow flow section has a second depth, and the first depth is greater than the second depth to reduce the flow velocity of the blood sample in the micro flow channel structure.

4. The micro flow channel chip as in embodiment 3, further comprising a blood sample outlet having a diameter, connected to the second end of the slow flow section and extending from the second surface to the first surface of the body, for discharging the blood sample to be tested or processed out of the micro flow channel structure, wherein the diameter is 0.8-1.2mm, the first depth is 120 μm and 250 μm, and the second depth is 50-100 μm.

5. The micro flow channel chip of embodiment 1, wherein the substrate is made of acryl (PMMA), polyethylene terephthalate (PET), Polycarbonate (PC), Polydimethylsiloxane (PDMS), silicone rubber, plastic, or glass, and the body is made of acryl (PMMA), polyethylene terephthalate (PET), silicone rubber, or plastic.

6. The micro flow channel chip according to embodiment 1, wherein the first surface and the second surface are disposed opposite to each other.

7. A micro-channel structure, comprising a structure body for flowing a micro-fluid sample through the micro-channel structure to be tested or processed, wherein the structure body comprises: a detection section having a first end and a second end, wherein the first end is used for receiving the microfluidic sample, and the second end is used for discharging the microfluidic sample after being inspected or processed; a buffering section having a third end and a fourth end, wherein the third end is connected to the second end and is configured to receive the assayed or processed microfluidic sample, and the fourth end is configured to discharge the assayed or processed microfluidic sample to a recovery area; and a slow flow main channel which is positioned between the third end and the fourth end and is used for reducing the speed of the third end receiving the tested or processed microfluidic sample.

8. The micro flow channel structure of embodiment 7, wherein the slow flow main flow channel is a zigzag structure (labyrinth), and the micro fluid sample is a body fluid or a bacterial fluid.

9. The micro flow channel structure of embodiment 7, further comprising a micro fluid sample outlet connected to the fourth end of the slow flow section, wherein the fourth end is configured to discharge the tested or processed micro fluid sample to the recovery area through the micro fluid sample outlet.

10. The micro flow channel structure according to embodiment 9, wherein: the width of the first end is 250 μm-1.5mm, and the depth is 220-250 μm; the width of the second end is 150-; the width of the third end is 150-250 μm, and the depth is 50-100 μm; and the diameter of the microfluidic sample outlet is 0.8-1.2 mm.

In conclusion, the present invention can use a novel concept to effectively capture a trace amount of circulating tumor cells in blood by matching the micro flow channel chip with the large beads, and reduce the capture error rate to determine the occurrence of cancer at an early stage. Furthermore, the utility model discloses a miniflow channel chip can increase the fluid resistance in the miniflow channel including crooked unhurried current district section to slow down the flow velocity of miniflow sample in the miniflow channel structure, can ensure that the biological material that wants to snatch is same kind of velocity of flow all the time when passing through the pearl body region, in order to increase the rate of snatching of the biological material of snatching of pearl body. Therefore, those skilled in the art can devise various modifications without departing from the scope of the appended claims.

[ description of reference ]

10 micro-channel chip

100 substrate

200 body

210 first surface

220 second surface

300 micro-channel structure

310 blood sample inlet

320 expansion section

330 resistance increasing section

340 detection section

341 first end

343 second end

350 slow flow section

351 first end

352 slow flow main flow channel

353 second end

360 blood sample outlet

40 beads

50 micro-channel structure

500 structure body

510 microfluidic sample inlet

520 resistance increasing section

530 detecting a segment

540 slow flow section

541 slow flow main flow channel

550 microfluidic sample outlet

60 beads

Claims

1. A micro flow channel chip, comprising:

a substrate;

the body is provided with a first surface and a second surface, wherein the second surface is closely covered on the substrate; and

the micro-channel structure is embedded in the second surface, so that the micro-channel structure forms a micro-channel between the body and the substrate, and a blood sample flows in the micro-channel structure, wherein the micro-channel structure comprises:

the slow flow section is provided with a slow flow main flow channel which is of a repeated bending structure and used for reducing the flow speed of the blood sample in the micro flow channel structure.

2. The micro flow channel chip of claim 1, further comprising a detection section, and the slow flow section further comprises a first end and a second end, wherein the first end of the slow flow section is connected to the detection section, wherein the detection section is used for testing or processing the blood sample and discharging the tested or processed blood sample, and the first end of the slow flow section is used for receiving the tested or processed blood sample.

3. The micro flow channel chip of claim 2, wherein the detection section has a first depth and the slow flow section has a second depth, the first depth being greater than the second depth to reduce the flow velocity of the blood sample in the micro flow channel structure.

4. The micro flow channel chip of claim 3, further comprising a blood sample outlet having a diameter, connected to the second end of the slow flow section, and extending from the second surface to the first surface of the body for discharging the blood sample to be tested or processed out of the micro flow channel structure, wherein the diameter is 0.8-1.2mm, the first depth is 120 μm and 250 μm, and the second depth is 50-100 μm.

5. The micro flow channel chip of claim 1, wherein the substrate is made of acryl, polyethylene terephthalate, polycarbonate, polydimethylsiloxane, silicone, rubber, plastic, or glass, and the body is made of acryl, polyethylene terephthalate, polycarbonate, polydimethylsiloxane, silicone, rubber, or plastic.

6. The micro flow channel chip of claim 1, wherein the first surface is disposed opposite to the second surface.

7. A micro flow channel structure, comprising a structure body for flowing a micro fluid sample through the micro flow channel structure to be tested or processed, wherein the structure body comprises:

a detection section having a first end and a second end, wherein the first end is used for receiving the microfluidic sample, and the second end is used for discharging the microfluidic sample after being inspected or processed;

a buffering section having a third end and a fourth end, wherein the third end is connected to the second end and is configured to receive the assayed or processed microfluidic sample, and the fourth end is configured to discharge the assayed or processed microfluidic sample to a recovery area; and

and the slow flow main channel is positioned between the third end and the fourth end and used for reducing the speed of the third end receiving the tested or processed microfluidic sample.

8. The micro flow channel structure of claim 7, wherein the slow flow main flow channel is a repeated bending structure, and the micro fluid sample is a body fluid or a bacterial fluid.

9. The micro flow channel structure of claim 7, further comprising a micro fluid sample outlet connected to the fourth end of the slow flow section, wherein the fourth end is configured to discharge the tested or processed micro fluid sample to the recovery area through the micro fluid sample outlet.

10. The micro flow channel structure of claim 9 wherein:

the width of the first end is 250 μm-1.5mm, and the depth is 220-250 μm;

the width of the second end is 150-;

the width of the third end is 150-250 μm, and the depth is 50-100 μm; and

the diameter of the microfluidic sample outlet is 0.8-1.2 mm.