Digital microfluidic chip

Abstract

An embodiment of the present disclosure provides a digital microfluidic chip, comprising a substrate and a cover plate. A ground electrode and a plurality of control electrodes are provided on the substrate, and a dielectric layer and a first hydrophobic layer are sequentially coated on the plurality of control electrodes. The plurality of control electrodes are used to drive the movement of reagents so as to perform methylation conversion, pre-library preparation, hybridization capture and final library preparation for the sample to be tested. The cover plate covers and is connected to the substrate, and sample injection holes for injecting reagents are provided at positions on the cover plate corresponding to at least a part of the plurality of control electrodes. A conductive layer and a second hydrophobic layer are sequentially coated on the side of the cover plate facing the substrate, and a gap for the movement of reagents is formed between the second hydrophobic layer on the cover plate and the first hydrophobic layer on the plurality of control electrodes, and the conductive layer is electrically connected to the ground electrode through a conductive glue.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of microfluidics, and more particularly, to a digital microfluidics chip. Background Art

[0002] In the research and development of pan-cancer early screening products, the main technical route is based on the methylation of deoxyribonucleic acid (DNA). DNA methylation is a stable silencing mark that plays a key role in the epigenetic silencing transcription process. DNA methylation does not affect base complementary pairing (Watson-Crick pair), but it affects the interaction between DNA and protein. DNA methylation forms a regulatory layer on top of the DNA sequence, which mainly affects gene expression regulation, chromosome stability, aneuploidy, and cell differentiation. A person's different organs and tissues have only one set of DNA sequences, but unlike DNA sequences, DNA methylation characteristics are highly tissue-specific. Different organs and tissues, as well as whether cancer occurs, show different methylation spectrum characteristics. Therefore, early cancer screening can be achieved by detecting DNA methylation in the blood, and the tissue origin of the cancer can be traced, that is, to determine which part of the cancer is.

[0003] Whole-genome methylation sequencing (WGBS) is a common method for detecting DNA methylation in the genome. WGBS involves treating DNA with sodium bisulfite to convert unmethylated cytosine to uracil. Sequencing is then performed, and the ratio of uracil to cytosine is used to determine which sites in the DNA sequence are methylated.

[0004] Conventional WGBS library construction processes include two options: manual library construction and automated workstation library construction. In the manual library construction option, huge manpower and material resources are required. Manual completion of the process requires a large area of ​​site and a batch of instruments. In addition, people will inevitably make mistakes when operating complex processes, resulting in a low average success rate for manual library construction. The success rate and cost-effectiveness of the solution for automated library construction using an automated workstation are better than manual operation. The automated workstation integrates many laboratory equipment functions, occupies a small area, is more efficient, has more stable data performance, and improves efficiency. However, the automated workstation cannot achieve full process automation, and manual intervention is still required during the library construction process. In addition, the automated workstation library construction solution has disadvantages such as high cost of consumables, expensive instruments, and high capital investment for enterprises. Summary of the Invention

[0005] In one aspect of the present disclosure, a digital microfluidic chip is provided, comprising a substrate and a cover plate. A ground electrode and a plurality of control electrodes are provided on the substrate, and a dielectric layer and a first hydrophobic layer are sequentially coated on the plurality of control electrodes. The plurality of control electrodes are used to drive the movement of reagents so as to perform methylation conversion, pre-library preparation, hybridization capture and final library preparation for the sample to be tested. The cover plate covers and is connected to the substrate, and sample injection holes for injecting reagents are provided at positions on the cover plate corresponding to at least a part of the plurality of control electrodes. A conductive layer and a second hydrophobic layer are sequentially coated on one side of the cover plate facing the substrate, and a gap for the movement of reagents is formed between the second hydrophobic layer on the cover plate and the first hydrophobic layer on the plurality of control electrodes, and the conductive layer is electrically connected to the ground electrode through a conductive glue.

[0006] It should be understood that the content described in this content section is not intended to limit the key features or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0008] Figure 1 shows a schematic structural diagram of a digital microfluidic chip according to an embodiment of the present disclosure;

[0009] Figure 2 Shown Figure 1 An exploded schematic diagram of the digital microfluidic chip is shown;

[0010] Figure 3 A schematic structural diagram of a positioning framework according to an embodiment of the present disclosure is shown;

[0011] Figure 4 A schematic diagram of the internal structure of a digital microfluidic chip according to an embodiment of the present disclosure is shown;

[0012] Figure 5 A schematic structural diagram of a substrate according to an embodiment of the present disclosure is shown;

[0013] Figure 6 shows an example arrangement of heating blocks according to one embodiment of the present disclosure;

[0014] Figure 7 and Figure 8 A schematic structural diagram of a cover plate according to an embodiment of the present disclosure is shown.

[0015] Description of reference numerals:

[0016] 100-digital microfluidic chip;

[0017] 1-substrate, 101-control electrode, 102-ground electrode, 11-methylation conversion unit, 12-prelibrary preparation unit, 13-merging unit, 131-input electrode, 132-merging electrode, 133-output electrode, 14-hybridization capture unit, 15-final library preparation unit, 16-redundant unit, 17-medium layer, 18-first hydrophobic layer, 19-probe contact point;

[0018] 2-cover plate, 20-conductive layer, 21-second hydrophobic layer, 22-sample loading hole, 23-binding portion, 24-protrusion;

[0019] 3-positioning frame, 31-interior space;

[0020] 40-gap, 41-reagent, 42-bonding layer, 43-conductive adhesive;

[0021] 50-probe, 51-heating block, 511-first heating block, 512-second heating block, 513-third heating block, 514-fourth heating block, 515-fifth heating block, 516-sixth heating block, 517-seventh heating block, 518-eighth heating block, 52-magnet module, 53-optical detection module. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0023] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "one example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or identical objects.

[0024] DNA methylation testing primarily involves whole blood collection, plasma separation, circulating DNA (cfDNA) extraction, methylation conversion, pre-library preparation, hybridization capture, final library preparation, and next-generation sequencing (NGS). These stages require numerous instruments, equipment, and space, resulting in high consumable costs and lengthy manual operations.

[0025] Conventional WGBS database construction processes include manual operation and automated workstation construction. As mentioned above, manual WGBS database construction requires significant human and material resources. Manual completion requires a large area and a large number of instruments, and human errors are inevitable when operating complex processes, resulting in a low average success rate for manual database construction. The automated workstation-based WGBS database construction process cannot achieve full automation, requiring manual intervention during the construction process. Furthermore, the automated workstation-based approach has drawbacks such as high consumable costs, expensive instruments, and high capital investment for the enterprise.

[0026] To solve the above problems, the embodiments of the present disclosure provide a digital microfluidic chip, which can realize the addition of cfDNA after extraction into the digital microfluidic chip, and automatically complete the processes of methylation conversion, pre-library preparation, hybridization capture and final library preparation inside the digital microfluidic chip to improve the success rate of library construction and reduce the cost of library construction. Figures 1 to 8 Embodiments of the present disclosure are described.

[0027] Figure 1 FIG. 1 shows a schematic structural diagram of a digital microfluidic chip 100 according to an embodiment of the present disclosure. Figure 2 Shown Figure 1 The exploded schematic diagram of the digital microfluidic chip 100 is shown in FIG. Figure 1 and Figure 2 As shown, the digital microfluidic chip 100 described herein generally includes a substrate 1, a cover plate 2 and a positioning frame 3. The cover plate 2 covers the substrate 1 and is connected to the substrate 1. As an example, the cover plate 2 can be bonded to the substrate 1 by laser (e.g., ultraviolet light, UV). It should be understood that the cover plate 2 can be assembled with the substrate 1 by any appropriate connection method, and the embodiments of the present disclosure are not limited to this. In the embodiments of the present disclosure, for ease of understanding and description, the substrate 1 may also be referred to as the lower substrate, and the cover plate 2 may also be referred to as the upper cover plate.

[0028] After assembling the cover plate 2 and the base plate 1, the base plate 1 can be secured to the positioning frame 3 using screws. The positioning frame 3 can be placed on the library construction instrument to begin the library construction process. It should be understood that the base plate 1 can be secured to the positioning frame 3 using any suitable mounting method, and the embodiments of the present disclosure are not limited thereto.

[0029] In one embodiment, substrate 1 comprises at least one of indium tin oxide (ITO) glass, a printed circuit board (PCB), and a conductive polycarbonate (PC) plastic board. In other embodiments, substrate 1 may comprise any available or future developed substrate type, and such implementations fall within the scope of the present disclosure. As an example, substrate 1 may be fabricated by one or more of screen printing, computer numerically controlled precision machining (CNC machining), dry etching, and wet etching.

[0030] Figure 3 FIG. 3 shows a schematic structural diagram of a positioning frame 3 according to an embodiment of the present disclosure. Figure 3 As shown, the positioning frame 3 includes an internal space 31, which is used to avoid the heating block in the library preparation instrument. When the digital microfluidic chip 100 is placed on the library preparation instrument, the heating block can be located in the internal space 31 of the positioning frame 3. In addition, to reduce the weight of the digital microfluidic chip 100, multiple through holes can be provided in the positioning frame 3 to reduce weight.

[0031] Figure 4 FIG. 1 shows a schematic diagram of the internal structure of a digital microfluidic chip 100 according to an embodiment of the present disclosure.

[0032] In one embodiment, Figure 4 As shown, a ground electrode 102 and a plurality of control electrodes 101 are provided on the substrate 1. The ground electrode 102 can be electrically connected to a power supply to receive a zero potential. For example, the ground electrode 102 can receive a zero potential provided by a power supply via an electrowetting on dielectric (EWOD) probe 50. Similarly, a plurality of control electrodes 101 can receive a driving voltage provided by a power supply via an EWOD probe 50. A dielectric layer 17 and a first hydrophobic layer 18 are sequentially coated on the plurality of control electrodes 101. That is, the dielectric layer 17 is coated on the control electrode 101, and the first hydrophobic layer 18 is coated on the matrix layer 17. The dielectric layer 17 can prevent current from flowing through the reagent 41 to prevent the reagent 41 from being electrolyzed. The first hydrophobic layer 18 directly contacts the reagent 41 so that the reagent 41 moves between different control electrodes 101 under the action of the driving voltage, thereby performing processes such as methylation conversion, pre-library preparation, hybridization capture and final library preparation for the sample to be tested.

[0033] In one embodiment, dielectric layer 17 includes at least one of dichloroparaxylene dimer, polyimide film, silicon nitride, silicon oxide, aluminum oxide, and tantalum oxide. In other embodiments, dielectric layer 17 may include any available or future-developed dielectric material, and such implementations fall within the scope of the present disclosure. For example, matrix layer 17 may be formed by one or more of bonding, chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD).

[0034] In one embodiment, Figure 4 As shown, the cover plate 2 can be connected to the substrate 1 through a bonding layer 42. A sample injection hole 22 for injecting the reagent 41 is provided at a position on the cover plate 2 corresponding to at least a portion of the multiple control electrodes 101. The side of the cover plate 2 facing the substrate 1 is sequentially coated with a conductive layer 20 and a second hydrophobic layer 21. That is, the conductive layer 20 is coated on the cover plate 2, and the second hydrophobic layer 21 is coated on the conductive layer 20. A gap 40 for the reagent 41 to move is formed between the second hydrophobic layer 21 on the cover plate 2 and the first hydrophobic layer 18 on the multiple control electrodes 101. In order to protect the reagent 41, silicone oil can be provided in the gap 40. The conductive layer 20 is electrically connected to the ground electrode 102 through a conductive glue 43, so that the conductive layer 20 is also at zero potential. The second hydrophobic layer 21 directly contacts the reagent 41, so that the reagent 41 can move between different control electrodes 101 under the action of the driving voltage.

[0035] like Figure 4 As shown, after the digital microfluidic chip 100 is placed on the library construction instrument, the heating block 51 and the magnet module 52 in the library construction instrument are located below the substrate 1. The heating block 51 can be located at different positions below the substrate 1 to heat the reagents 41 on different control electrodes 101, thereby performing processes such as methylation conversion, pre-library preparation, hybridization capture, and final library preparation for the sample to be tested. The magnet module 52 can drag the magnetic beads in the gap 40 to move to transfer DNA between different control electrodes 101. The library construction instrument can also include a light detection module 53 arranged above the upper cover plate 2 for detecting DNA concentration.

[0036] The disclosed embodiments utilize digital microfluidics to fully automate WGBS library construction, eliminating the need for manual intervention. Consumable material costs are only 50% of those associated with automated workstations, 40% of those associated with manual operation, and instrument costs are only 10% of those associated with workstations. Consequently, compared to conventional manual and automated workstation-based library construction, this approach improves library construction success rates and significantly reduces costs.

[0037] Figure 5 FIG. 1 shows a schematic structural diagram of a substrate according to an embodiment of the present disclosure. Figure 6 An example arrangement of heating blocks according to one embodiment of the present disclosure is shown. Figure 5 and Figure 6As shown, multiple control electrodes 101 form a methylation conversion unit 11, a pre-library preparation unit 12, a merging unit 13, a hybridization capture unit 14 and a final library preparation unit 15. The methylation conversion unit 11 is used to perform methylation conversion on multiple samples. The pre-library preparation unit 12 is adjacent to the methylation conversion unit 11 to perform pre-library preparation on multiple samples that have undergone methylation conversion. The merging unit 13 is adjacent to the pre-library preparation unit 12 to merge multiple samples prepared by the pre-library. The hybridization capture unit 14 is adjacent to the merging unit 13 to capture specific DNA sequences from the merged multiple samples. The final library preparation unit 15 is configured to perform amplification on a specific DNA sequence, such as polymerase chain reaction (PCR) amplification.

[0038] In one embodiment, Figure 5 As shown, the methylation conversion unit 11 includes a plurality of control electrodes 101 arranged side by side along a first direction. Figure 5 and Figure 6 It is shown as a substantially horizontal direction in the figure. It should be understood that when the substrate 1 is arranged in other directions, the first direction is changed to other directions accordingly. Each group of control electrodes 101 is used to perform methylation conversion on a corresponding sample in a plurality of samples. Each group of control electrodes 101 includes a plurality of rows of control electrodes 101 arranged in a second direction substantially perpendicular to the first direction and connecting electrodes provided between control electrodes 101 in adjacent rows. The second direction is Figure 5 and Figure 6 In each group of control electrodes 101, by controlling the voltage applied to the control electrodes 101, the reagents 41 can be moved within each row of control electrodes 101 and between different rows of control electrodes 101, so as to perform operations such as moving, splitting, merging and mixing the reagents 41. As an example, Figure 5 and Figure 6 Figure 2 shows that the methylation conversion unit 11 includes four sets of control electrodes 101 for processing four samples. In other embodiments, the methylation conversion unit 11 may include more or fewer sets of control electrodes 101 for processing more or fewer samples. For example, the methylation conversion unit 11 may include two, three, five, or six sets of control electrodes 101 for processing corresponding samples.

[0039] It should be noted that the numbers, values, etc. mentioned above and elsewhere in this disclosure are exemplary and are not intended to limit the scope of this disclosure in any way. Any other appropriate numbers and values ​​are possible.

[0040] In one embodiment, Figure 6As shown, after the digital microfluidic chip 100 is placed on a library preparation instrument (not shown), the methylation conversion unit 11 is located above the first heating block 511 and the second heating block 512 of the library preparation instrument. The first heating block 511 and the second heating block 512 are used to heat the reagent 41 on the control electrode 101 in the methylation conversion unit 11, thereby performing methylation conversion on multiple samples.

[0041] like Figure 5 As shown, the pre-library preparation unit 12 is adjacent to the methylation conversion unit 11 to perform pre-library preparation on multiple samples that have undergone methylation conversion. In one embodiment, the pre-library preparation unit 12 includes multiple groups of control electrodes 101 arranged side by side in a horizontal direction. Each group of control electrodes 101 is adjacent to a corresponding group of control electrodes 101 in the methylation conversion unit 11 to perform pre-library preparation on multiple samples that have undergone methylation conversion. Each group of control electrodes 101 in the pre-library preparation unit 12 includes multiple rows of control electrodes 101 arranged in a vertical direction and connecting electrodes arranged between adjacent rows of control electrodes 101. Within each group of control electrodes 101 in the pre-library preparation unit 12, by controlling the voltage applied to the control electrodes 101, the reagents 41 can be moved within each row of control electrodes 101 and between different rows of control electrodes 101, thereby performing operations such as moving, splitting, merging, and mixing the reagents 41. The number of groups of control electrodes 101 in the pre-library preparation unit 12 corresponds to the number of groups of control electrodes 101 in the methylation conversion unit 11. Figure 5 and Figure 6 , the pre-library preparation unit 12 includes four sets of control electrodes 101 for processing four methylation-converted samples. In other embodiments, the pre-library preparation unit 12 may include more or fewer sets of control electrodes 101 for processing more or fewer methylation-converted samples. For example, the pre-library preparation unit 12 may include two, three, five, or six sets of control electrodes 101 for processing corresponding samples.

[0042] In one embodiment, Figure 6 As shown, after the digital microfluidic chip 100 is placed on the library preparation instrument, the pre-library preparation unit 12 is located above the third heating block 513, the fourth heating block 514, and the fifth heating block 515 of the library preparation instrument. The third heating block 513, the fourth heating block 514, and the fifth heating block 515 are used to heat the reagent 41 on the control electrode 101 in the pre-library preparation unit 12, thereby performing pre-library preparation on multiple samples that have undergone methylation conversion.

[0043] like Figure 5As shown, the merging unit 13 is adjacent to the pre-library preparation unit 12 to merge multiple samples prepared by the pre-library. In one embodiment, the merging unit 13 includes multiple input electrodes 131, multiple merging electrodes 132, and output electrodes 133. The multiple input electrodes 131 are respectively adjacent to a corresponding set of control electrodes 101 in the pre-library preparation unit 12 to receive multiple samples prepared by the pre-library. The multiple merging electrodes 132 are arranged side by side in a horizontal direction and adjacent to the multiple input electrodes 131. The output electrode 133 is adjacent to the multiple merging electrodes 132 to move the merged multiple samples to the hybridization capture unit 14. Within the merging unit 13, by controlling the voltage applied to the control electrodes 101, each sample prepared by the pre-library can be moved to the merging electrode 132 via the corresponding input electrode 131, merged at the merging electrode 132, and then moved to the output electrode 133 after merging. Subsequently, the merged samples can be moved to the hybridization capture unit 14 via the output electrode 133.

[0044] like Figure 5 As shown, the hybridization capture unit 14 is adjacent to the merging unit 13 to capture specific DNA sequences from the merged multiple samples. In one embodiment, the hybridization capture unit 14 includes multiple rows of control electrodes 101 arranged side by side and connecting electrodes provided between the control electrodes 101 in adjacent rows. A row of control electrodes 101 in the hybridization capture unit 14 is adjacent to the merging unit 13 to receive the merged multiple samples. As an example, Figure 5 As shown, the first row of control electrodes 101 of the hybridization capture unit 14 is adjacent to the output electrode 133 of the merging unit 13 to receive the merged multiple samples. By controlling the voltage applied to the control electrodes 101 of the hybridization capture unit 14, the merged samples can be moved within each row of control electrodes 101 and between different rows of control electrodes 101, so that operations such as moving, splitting, merging, and mixing the merged samples can be performed.

[0045] In one embodiment, Figure 6 As shown, after the digital microfluidic chip 100 is placed on the library preparation instrument, the hybridization capture unit 14 is located above the sixth heating block 613, the seventh heating block 517, and the eighth heating block 518 of the library preparation instrument. The sixth heating block 613, the seventh heating block 517, and the eighth heating block 518 are used to heat the sample on the control electrode 101 in the hybridization capture unit 14, thereby performing hybridization capture on the merged sample.

[0046] The final library preparation unit 15 is configured to perform amplification on a specific DNA sequence, such as PCR amplification. The final library preparation unit 15 includes multiple rows of control electrodes 101 arranged side by side and connecting electrodes arranged between adjacent rows of control electrodes 101. The final library preparation unit 15 is spaced apart from the methylation conversion unit 11, the pre-library preparation unit 12, the merging unit 13 and the hybridization capture unit 14. The specific DNA sequence captured on the hybridization capture unit 14 can be transferred to the final library preparation unit 15 by magnetic beads. In the final library preparation unit 15, by controlling the voltage applied to the control electrode 101, the reagent 41 can be moved within each row of control electrodes 101 and between different rows of control electrodes 101, so as to perform operations such as moving, splitting, merging and mixing the reagent 41. Figure 6 As shown, after the digital microfluidic chip 100 is placed on the library preparation instrument, the final library preparation unit 15 is located above the sixth heating block 613, the seventh heating block 517, and the eighth heating block 518 of the library preparation instrument. The sixth heating block 613, the seventh heating block 517, and the eighth heating block 518 can heat the specific DNA sequence on the control electrode 101 in the final library preparation unit 15, thereby amplifying the specific DNA sequence.

[0047] In one embodiment, Figure 5 As shown, the plurality of control electrodes 101 further form a redundant unit 16, which is adjacent to the merging unit 13 to receive the merged multiple samples. The redundant unit 16 can be used as a backup design, and when the remaining control electrodes 101 are insufficient, the merged samples can be temporarily transferred to the redundant unit 16.

[0048] In one embodiment, Figure 5 As shown, a plurality of probe contact points 19 are provided on the periphery of the substrate 1 , and each probe contact point 19 is electrically connected to one or more control electrodes 101 to apply a driving voltage to the corresponding control electrode 101 .

[0049] Figure 7 and Figure 8 A schematic structural diagram of a cover plate according to an embodiment of the present disclosure is shown. Figure 7 The top side of the cover plate 2 is shown, ie the side facing away from the cover plate 1 . Figure 8 The underside of the cover plate 2 is shown, ie the side facing toward the cover plate 1 .

[0050] In one embodiment, Figure 7 and Figure 8As shown, the cover plate 2 is provided with sample loading holes 22 corresponding to each row of control electrodes 101 of the methylation conversion unit 11, the pre-library preparation unit 12, the hybridization capture unit 14, and the final library preparation unit 15. Reagents 41 can be added to the gap 40 between the substrate 1 and the cover plate 2 through the sample loading holes 22.

[0051] In one embodiment, Figure 8 As shown, a plurality of bonding portions 23 are provided on the side of the cover plate 2 facing the substrate 1, and the plurality of bonding portions 23 are connected to the substrate 1. The plurality of bonding portions 23 can be bonded to the substrate 1 by, for example, laser (e.g., ultraviolet light, UV). A raised portion 24 is provided at a position corresponding to the merging unit 13 on the side of the cover plate 2 facing the substrate 1. The height of the raised portion 24 is less than the height of the bonding portion 23. By providing the raised portion 24, the height of the gap 40 between the cover plate 2 and the control electrode 101 of the merging unit 13 can be reduced, thereby providing a smaller volume of droplets and achieving more precise and subtle control.

[0052] Embodiments of the present disclosure are also embodied in the following examples.

[0053] Example 1. A digital microfluidic chip comprising:

[0054] a substrate, on which a ground electrode and a plurality of control electrodes are disposed, wherein a dielectric layer and a first hydrophobic layer are sequentially coated on the plurality of control electrodes, and the plurality of control electrodes are used to drive the movement of reagents to perform methylation conversion, pre-library preparation, hybridization capture, and final library preparation on a sample to be tested; and

[0055] A cover plate, the cover plate covers and is connected to the substrate, and sample injection holes for injecting reagents are provided at positions on the cover plate corresponding to at least a portion of the multiple control electrodes. A conductive layer and a second hydrophobic layer are sequentially coated on the side of the cover plate facing the substrate, a gap for the movement of reagents is formed between the second hydrophobic layer on the cover plate and the first hydrophobic layer on the multiple control electrodes, and the conductive layer is electrically connected to the ground electrode via a conductive glue.

[0056] Example 2. A digital microfluidic chip according to Example 1, wherein the multiple control electrodes form a methylation conversion unit, a pre-library preparation unit, a merging unit, a hybridization capture unit and a final library preparation unit, the methylation conversion unit is used to perform methylation conversion on multiple samples, the pre-library preparation unit is adjacent to the methylation conversion unit to perform pre-library preparation on multiple samples that have undergone methylation conversion, the merging unit is adjacent to the pre-library preparation unit to merge multiple samples that have undergone pre-library preparation, the hybridization capture unit is adjacent to the merging unit to capture specific DNA sequences from the merged multiple samples, and the final library preparation unit is configured to perform amplification on the specific DNA sequence.

[0057] Example 3. A digital microfluidic chip according to Example 2, wherein the methylation conversion unit includes a plurality of groups of control electrodes arranged side by side along a first direction, each group of control electrodes is used to perform methylation conversion on a corresponding sample among the plurality of samples, each group of control electrodes includes a plurality of rows of control electrodes arranged along a second direction perpendicular to the first direction and connecting electrodes arranged between adjacent rows of control electrodes, and the cover plate is provided with the sample loading holes corresponding to each row of control electrodes of the methylation conversion unit.

[0058] Example 4. A digital microfluidic chip according to Example 3, wherein the pre-library preparation unit includes multiple groups of control electrodes arranged side by side along the first direction, each group of control electrodes is adjacent to a corresponding group of control electrodes in the methylation conversion unit, so as to perform pre-library preparation on multiple samples that have undergone methylation conversion, each group of control electrodes of the pre-library preparation unit includes multiple rows of control electrodes arranged along the second direction and connecting electrodes arranged between adjacent rows of control electrodes, and the cover plate is provided with the sample loading holes corresponding to each row of control electrodes of the pre-library preparation unit.

[0059] Example 5. A digital microfluidic chip according to Example 4, wherein the merging unit includes a plurality of input electrodes, a plurality of merging electrodes, and an output electrode, the plurality of input electrodes are respectively adjacent to a corresponding set of control electrodes in the pre-library preparation unit to receive a plurality of samples prepared by the pre-library, the plurality of merging electrodes are arranged side by side along the first direction and adjacent to the plurality of input electrodes, and the output electrode is adjacent to the plurality of merging electrodes to move the merged plurality of samples to the hybridization capture unit.

[0060] Example 6. A digital microfluidic chip according to Example 2, wherein the hybridization capture unit includes multiple rows of control electrodes arranged side by side and connecting electrodes arranged between adjacent rows of control electrodes, a row of control electrodes of the hybridization capture unit is adjacent to the merging unit to receive the merged multiple samples, and the cover plate is provided with the sample loading holes corresponding to each row of control electrodes of the hybridization capture unit.

[0061] Example 7. The digital microfluidic chip according to Example 2, wherein the final library preparation unit includes multiple rows of control electrodes arranged side by side and connecting electrodes arranged between adjacent rows of control electrodes, the final library preparation unit is spaced apart from the methylation conversion unit, the pre-library preparation unit, the merging unit and the hybridization capture unit, and the cover plate is provided with the sample loading holes corresponding to each row of control electrodes of the final library preparation unit.

[0062] Example 8. The digital microfluidic chip according to Example 2, wherein the plurality of control electrodes further form a redundant unit, the redundant unit being adjacent to the merging unit to receive the merged plurality of samples.

[0063] Example 9. A digital microfluidic chip according to Example 2, wherein a plurality of coupling portions are provided on the side of the cover plate facing the substrate, the plurality of coupling portions are connected to the substrate, and a protrusion is provided at a position corresponding to the merging unit on the side of the cover plate facing the substrate, and the height of the protrusion is smaller than the height of the coupling portion.

[0064] Example 10. The digital microfluidic chip according to Example 1 further includes a positioning frame connected to the substrate.

[0065] Example 11. A digital microfluidic chip according to any one of Examples 1 to 10, wherein the substrate comprises at least one of ITO glass, a PCB board, and a conductive PC plastic board.

[0066] Example 12. A digital microfluidic chip according to any one of Examples 1 to 10, wherein the dielectric layer comprises at least one of dichloroparaxylene dimer, polyimide film, silicon nitride, silicon oxide, aluminum oxide and tantalum oxide.

[0067] While various embodiments of the present disclosure have been described above, the above descriptions are illustrative, non-exhaustive, and not intended to be limiting of the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A digital microfluidic chip (100), comprising: A substrate (1) is provided with a ground electrode (102) and a plurality of control electrodes (101), the plurality of control electrodes (101) are sequentially coated with a dielectric layer (17) and a first hydrophobic layer (18), the plurality of control electrodes (101) are used to drive the movement of a reagent (41) so as to perform methylation conversion, prelibrary preparation, hybridization capture and final library preparation on a sample to be tested; wherein the plurality of control electrodes (101) form a methylation conversion unit (11), a prelibrary preparation unit (12), a merging unit (13), a hybridization capture unit (14) and a final library preparation unit (15), the methylation conversion unit (11) is used to perform methylation conversion on multiple samples, the pre-library preparation unit (12) is adjacent to the methylation conversion unit (11) to perform pre-library preparation on the multiple samples that have undergone methylation conversion, the merging unit (13) is adjacent to the pre-library preparation unit (12) to merge the multiple samples that have undergone pre-library preparation, the hybridization capture unit (14) is adjacent to the merging unit (13) to capture specific DNA sequences from the merged multiple samples, and the final library preparation unit (15) is configured to perform amplification on the specific DNA sequence; and A cover plate (2) covers and is connected to the substrate (1); a sample injection hole (22) for injecting a reagent (41) is provided on the cover plate (2) at a position corresponding to at least a portion of the electrodes among the plurality of control electrodes (101); a conductive layer (20) and a second hydrophobic layer (21) are sequentially coated on the side of the cover plate (2) facing the substrate (1); a gap (40) for the reagent (41) to move is formed between the second hydrophobic layer (21) on the cover plate (2) and the first hydrophobic layer (18) on the plurality of control electrodes (101); and the conductive layer (20) is electrically connected to the ground electrode (102) via a conductive adhesive (43).

2. The digital microfluidic chip (100) according to claim 1, wherein the methylation conversion unit (11) comprises a plurality of groups of control electrodes (101) arranged side by side along a first direction, each group of control electrodes (101) is used to perform methylation conversion on a corresponding sample among the plurality of samples, each group of control electrodes (101) comprises a plurality of rows of control electrodes (101) arranged along a second direction perpendicular to the first direction and connecting electrodes arranged between adjacent rows of control electrodes (101), and the cover plate (2) is provided with the sample loading holes (22) corresponding to each row of control electrodes (101) of the methylation conversion unit (11).

3. The digital microfluidic chip (100) according to claim 2, wherein the pre-library preparation unit (12) comprises a plurality of groups of control electrodes (101) arranged side by side along the first direction, each group of control electrodes (101) being adjacent to a corresponding group of control electrodes (101) in the methylation conversion unit (11) so as to perform pre-library preparation on a plurality of samples converted by methylation, each group of control electrodes (101) of the pre-library preparation unit (12) comprises a plurality of rows of control electrodes (101) arranged along the second direction and connecting electrodes arranged between adjacent rows of control electrodes (101), and the cover plate (2) is provided with the sample loading holes (22) corresponding to each row of control electrodes (101) of the pre-library preparation unit (12).

4. The digital microfluidic chip (100) according to claim 3, wherein the merging unit (13) comprises a plurality of input electrodes (131), a plurality of merging electrodes (132), and an output electrode (133), the plurality of input electrodes (131) being respectively adjacent to a corresponding group of control electrodes (101) in the pre-library preparation unit (12) to receive a plurality of samples prepared by the pre-library, the plurality of merging electrodes (132) being arranged side by side along the first direction and adjacent to the plurality of input electrodes (131), and the output electrode (133) being adjacent to the plurality of merging electrodes (132) to move the merged plurality of samples to the hybridization capture unit (14).

5. The digital microfluidic chip (100) according to claim 1, wherein the hybridization capture unit (14) comprises a plurality of rows of control electrodes (101) arranged side by side and connecting electrodes arranged between adjacent rows of control electrodes (101), a row of control electrodes (101) of the hybridization capture unit (14) is adjacent to the merging unit (13) to receive the merged multiple samples, and the cover plate (2) is provided with the sample loading holes (22) corresponding to each row of control electrodes (101) of the hybridization capture unit (14).

6. The digital microfluidic chip (100) according to claim 1, wherein the final library preparation unit (15) comprises a plurality of rows of control electrodes (101) arranged side by side and connecting electrodes arranged between adjacent rows of control electrodes (101), the final library preparation unit (15) is spaced apart from the methylation conversion unit (11), the pre-library preparation unit (12), the merging unit (13) and the hybridization capture unit (14), and the cover plate (2) is provided with the sample loading holes (22) corresponding to each row of control electrodes (101) of the final library preparation unit (15).

7. The digital microfluidic chip (100) according to claim 1, wherein the plurality of control electrodes (101) further form a redundant unit (16), and the redundant unit (16) is adjacent to the merging unit (13) to receive the merged plurality of samples.

8. The digital microfluidic chip (100) according to claim 1, wherein a plurality of coupling portions (23) are provided on a side of the cover plate (2) facing the substrate (1), the plurality of coupling portions (23) are connected to the substrate (1), and a protrusion (24) is provided at a position corresponding to the merging unit (13) on a side of the cover plate (2) facing the substrate (1), and a height of the protrusion (24) is less than a height of the coupling portion (23).

9. The digital microfluidic chip (100) according to claim 1, further comprising a positioning frame (3), wherein the positioning frame (3) is connected to the substrate (1).

10. The digital microfluidic chip (100) according to any one of claims 1 to 9, wherein the substrate (1) comprises at least one of ITO glass, a PCB board and a conductive PC plastic board.

11. The digital microfluidic chip (100) according to any one of claims 1 to 9, wherein the dielectric layer (17) comprises at least one of dichloroparaxylene dimer, polyimide film, silicon nitride, silicon oxide, aluminum oxide and tantalum oxide.

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