Apparatus and method for producing microdroplets by freezing capillary

Abstract

The application provides a device and a method for generating microdroplets by freezing a capillary tube, comprising a thermostat, a vertically placed glass capillary tube connected to the thermostat through a fixing device, and a liquid collecting box placed below the glass capillary tube. The fixing device comprises a base, a vertical guide rail and a capillary tube clamp connected in sequence, the liquid collecting box is placed on the base, and the capillary tube clamp clamps the glass capillary tube so that the glass capillary tube is located above the liquid collecting box. The application absorbs liquid into the glass capillary tube through capillary tension, vertically places the glass capillary tube above the liquid collecting device, gradually reduces the ambient temperature to-40 DEG C, and forms microdroplets under the action of the end gas-liquid interface tension due to the expansion of the liquid when the liquid is frozen and the extrusion bulging caused by the volume expansion of the liquid when the liquid is frozen. The liquid in the glass capillary tube starts to freeze and drops from the lower end to obtain microdroplets.

Description

Technical Field

[0001] This invention relates to the field of microdroplet preparation technology, specifically to an apparatus and method for generating microdroplets via cryocapillary. Background Technology

[0002] Microdroplets have wide applications in fields such as physical chemistry, materials science, and biomedical engineering. Currently, they are mainly generated through T-shaped microchannels, which requires not only controlling a series of parameters such as flow rate, liquid interfacial tension, and channel size, but also introducing two immiscible liquids. Summary of the Invention

[0003] In order to solve the problems of the prior art, the present invention provides an apparatus and method for generating microdroplets through a cryogenic capillary, which eliminates the need to introduce a second liquid that may cause contamination, and does not require generation in a channel with a specific configuration, and the generated droplets are continuously controllable.

[0004] A device for generating microdroplets via a cryocapillary includes a thermostat, in which a vertically placed glass capillary is connected via a fixing device, and a liquid collection box is placed below the glass capillary.

[0005] In a further improvement, the liquid is water, a cell culture solution, or a liquid containing one or more of cells, DNA, RNA, and proteins.

[0006] In a further improvement, the fixing device includes a base, a vertical guide rail, and a capillary clamp connected in sequence. The liquid collection box is placed on the base, and the capillary clamp holds the glass capillary tube so that it is positioned above the liquid collection box.

[0007] In a further improvement, the liquid collection box can be a petri dish or a U-shaped tube.

[0008] As a further improvement, the constant temperature chamber is equipped with a temperature regulating device, which can regulate the temperature range from -40℃ to 20℃.

[0009] In a further improvement, the diameter of the glass capillary is 0.1 mm to 0.5 mm, and the angle between the glass capillary and the horizontal direction is 60-90°.

[0010] This invention also provides a method for generating microdroplets using a cryogenic capillary. Liquid is drawn into a glass capillary by capillary tension, and the capillary is placed vertically above a liquid collection device. The ambient temperature is gradually lowered to -40°C. Due to the volume expansion of the liquid during freezing, the end is compressed and bulges out. Under the action of the gas-liquid interfacial tension at the end, microdroplets are formed. The liquid in the glass capillary begins to freeze and drips from the lower end, thus obtaining microdroplets.

[0011] The device for generating microdroplets by a frozen capillary tube, the specific method comprises the following steps:

[0012] 1) The test liquid is sucked into the capillary tube by capillary tension and is hung on the support by the capillary clamp;

[0013] 2) The temperature of the thermostat is set to reduce to -40℃;

[0014] 3) As the temperature decreases, the liquid in the capillary tube begins to freeze, and droplets are generated at the lower end.

[0015] The radius r of the obtained droplet satisfies the relationship:

[0016] ;

[0017] Wherein is the contact angle of the liquid, is the liquid freeze expansion rate, l is the length of the liquid column, and R is the radius of the capillary tube.

[0018] The present application has the beneficial effects that:

[0019] 1. No second liquid which may cause pollution is introduced, and no channel of specific configuration is needed to generate, thus simplifying the preparation process.

[0020] 2. The generated droplets are continuously controllable and do not contact the channel, and the parameters are easy to adjust, and only by replacing capillary tubes with different inner diameters, droplets with specific radius can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0022] Figure 1 The structure of a specific embodiment of the present application is shown in the figure.

[0023] 1-thermostat, 2-glass capillary tube, 3-vertical guide rail, 4-base, 5-liquid collection box. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] A device for generating microdroplets by freezing a capillary tube, comprising a thermostat 1, a vertically placed glass capillary tube 2 connected by a fixing device inside the thermostat 1, and a liquid collection box 5 placed below the glass capillary tube 2.

[0026] The liquid is water, a cell culture solution, or a liquid containing one or more of cells, DNA, RNA, and proteins.

[0027] The fixing device comprises a base 4, a vertical guide rail 3, and a capillary tube clamp connected in sequence, the liquid collection box 5 is placed on the base 4, and the capillary tube clamp clamps the glass capillary tube 2 to be above the liquid collection box 5.

[0028] The liquid collection box 5 is a culture dish or a u-shaped tube.

[0029] The thermostat 1 is provided with a temperature adjusting device. The temperature adjusting device adjusts the temperature range to -40℃ to 20℃.

[0030] The diameter of the glass capillary tube 2 is 0.1mm to 0.5mm, and the angle between the glass capillary tube 2 and the horizontal direction is 60-90°.

[0031] A method for generating microdroplets by supercooling a capillary tube, the liquid is sucked into the glass capillary tube by capillary force, the glass capillary tube is vertically placed above the liquid collection device, the ambient temperature is gradually reduced to -40℃, the liquid in the glass capillary tube starts to freeze and drops from the lower end, and microdroplets are obtained.

[0032] The device for generating microdroplets by freezing a capillary tube is used, and the specific preparation method comprises the following steps:

[0033] 1) The test liquid is sucked into the capillary tube by capillary force and hung on the support by the capillary tube clamp;

[0034] 2) Set the temperature of the thermostat to reduce to -40℃;

[0035] 3) As the temperature decreases, the liquid in the capillary tube starts to freeze, and droplets are generated at the lower end.

[0036] The radius r of the obtained droplet satisfies the relationship:

[0037] ;

[0038] Wherein is the contact angle of the liquid, is the liquid swelling rate, l is the length of the liquid column, and R is the radius of the capillary tube.

[0039] The various embodiments described in this specification are presented as examples of the application. Each embodiment is presented in a way that emphasizes the differences between the embodiments and the other embodiments. In particular, the device embodiments are described in less detail than the method embodiments because they are substantially similar to the method embodiments. The above description is presented in terms of preferred embodiments of the application, but the scope of the application is not limited to the preferred embodiments. Any person skilled in the art who understands the technology described in this specification can easily make changes or replacements within the scope of the technology disclosed in this specification, without departing from the principles of the application. Therefore, the scope of the application should be determined by the scope of the claims.

Claims

1. An apparatus for generating microdroplets by freezing capillary tubes, characterized by: The application relates to a device for obtaining micro-droplets, comprising a thermostat (1), wherein a vertical glass capillary (2) is connected to the thermostat (1) through a fixing device, and a liquid collecting box (5) is placed below the glass capillary (2); the diameter of the glass capillary (2) is 0.1-0.5 mm, and the included angle between the glass capillary (2) and the horizontal direction is 60-90 degrees.

2. The device for generating microdroplets by freezing a capillary according to claim 1, characterized in that: The liquid is water, a cell culture solution or a liquid containing one or more of cells, DNA, RNA and proteins.

3. The device for generating microdroplets by freezing a capillary according to claim 1, characterized in that: The fixing device comprises a base (4), a vertical guide rail (3) and a capillary clamp which are sequentially connected, the liquid collecting box (5) is placed on the base (4), and the capillary clamp clamps the glass capillary (2) so that the glass capillary (2) is located above the liquid collecting box (5).

4. The device for generating microdroplets by freezing a capillary according to claim 1, characterized in that: The liquid collecting box (5) is a culture dish or a u-shaped tube.

5. The device for generating microdroplets by freezing a capillary according to claim 1, characterized in that: The thermostat (1) is provided with a temperature adjusting device.

6. The device for generating microdroplets by freezing a capillary according to claim 5, characterized in that: The temperature adjusting device adjusts the temperature interval to be -40-20 DEG C.

7. A method of producing microdroplets by supercooling a capillary, using the device for producing microdroplets by freezing a capillary according to claim 1, characterized in that: The liquid is absorbed into the glass capillary through capillary tension, the glass capillary is vertically placed above the liquid collecting device, the ambient temperature is gradually reduced to -40 DEG C, the liquid in the glass capillary starts to freeze and drops from the lower end, and micro-droplets are obtained.

8. The method of producing microdroplets by subcooling capillary tubes according to claim 7, wherein Specifically, the following steps are included: 1) the test liquid is absorbed into the capillary through capillary tension and is hung on a support through the capillary clamp; 2) the temperature of the thermostat is reduced to -40 DEG C; 3) as the temperature is reduced, the liquid in the capillary starts to freeze, and liquid droplets are generated at the lower end and drop.

9. The method of producing microdroplets by subcooling capillary according to claim 7 or 8, characterized in that: The radius r of the obtained liquid droplets satisfies the following relationship: ； wherein the contact angle of a liquid, the liquid frost heave ratio, l is the liquid column length, and R is the capillary radius.

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