CN108339578A - Drop injector and use its drop sample injection method - Google Patents

Abstract

The invention relates to a droplet sampler and a droplet sampler using the droplet sampler. The droplet sampler is a droplet sampler used in the field of microfluidic control, which can transfer a small amount of liquid samples from an open system to a closed micropipe system, especially in the form of water-in-oil. into the medium oil and transported in the micropipeline system. The droplet sampler includes a sample channel, which is used to suck and transport liquid samples, and the sample channel is connected to a module providing negative pressure; a medium channel, which is used to push a medium, and the medium channel is connected to a module providing positive pressure; The sample channel and the media channel are in fluid communication.

Description

Droplet sampler and droplet sampling method using the same

technical field

The invention relates to a droplet sampler and a droplet sampler using the droplet sampler, especially a droplet sampler used in the field of microfluidics, which can transfer a small amount of liquid samples from an open system to a closed microchannel The system, especially in the form of a liquid sample in a medium, such as water-in-oil, encapsulates a small amount of liquid sample in a medium, such as oil droplets, and transports it in a micro-channel system.

Background technique

Microfluidic chip technology is widely used in sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes. It is one of the most rapidly developing cutting-edge technologies and the most active fields of research. The manipulation of liquid samples is very important in the fields of chemistry, microbiology, biochemistry, molecular biology, and medical analysis. Liquid samples can be, for example, cell culture fluids, cell reaction fluids, protein solutions, DNA solutions, RNA solutions, different media, and other commonly used liquid samples in the fields of biology, chemistry, and medical analysis.

With the continuous development of microfluidic chip technology, the need to transfer a variety of liquid samples from an open system to a microchannel system has gradually become prominent, which has largely restricted the application and development of this technology. Common open systems in this field include, for example, various systems reacting in 96-well plates, centrifuge tubes, flasks, and sample tubes, and microchannel systems are, for example, microdroplet chips, capillary tubes, and microreactors.

Contents of the invention

The invention patent application of CN102426261A discloses a multi-sample sequence recording device for a microfluidic chip. The device includes a sample storage tube and a bidirectional pump. One end of the sample storage tube is provided with a sample inlet and outlet, and the other end is provided with a sample inlet and outlet control port. The two-way pump is connected with the sample inlet and outlet control port, and the method of using the above-mentioned loading device to load multiple samples sequentially is: through the negative pressure generated by the reversal of the two-way pump, the various samples are sequentially sucked into the sample storage tube in the reverse order of the sampling sequence, and each suction After a sample is inhaled isolation gas for isolation, since air is used for isolation of multiple samples, the sequential loading of multiple samples can be realized through the positive pressure generated by the forward rotation of the bidirectional pump.

The invention patent application of CN102740975A discloses a device and method for mixing and delivering fluid in a microfluidic system, wherein the device involved includes: an inlet, an outlet, an upstream channel part in fluid communication with the inlet, and a downstream channel in fluid communication with the outlet part, a discharge valve disposed between the upstream channel part and the downstream channel part, and a first fluid stored in at least one of the upstream channel part and the downstream channel part, wherein the device is sealed and constructed and arranged to Used to store the first fluid in the device for at least one hour prior to first use. The method includes providing a device comprising: a main channel; a first branch channel containing a first fluid; a second branch channel containing a second fluid, wherein the first branch channel and the second branch channel intersect connected at and fluidly connected to the main channel, and a discharge valve disposed between a portion of the first branch channel and a portion of the main channel; actuating the discharge valve; causing the first fluid and the second fluid to flow into the intersection substantially simultaneously, and mixing at least a portion of the first fluid and the second fluid to produce a mixed fluid. The invention patent application uses one or more discharge valves to controllably flow and/or mix fluid portions in a microfluidic system.

CN103454126A invention patent application discloses a capillary-based adjustable droplet generating device. The generator can be driven by positive or negative pressure to generate nanoliter to picoliter droplets. The generating device includes a T-shaped three-way joint 1, a variable diameter pipe 2, a dispersed phase input end 3, a continuous phase inflow end 4, and a liquid droplet suspension outflow end 5, a straight pipe of the T-shaped three-way joint 1, and a variable diameter pipe 2 The larger inner diameter end is connected, and one end of the capillary, that is, the tip is thinned to 2-50 microns and used as the dispersed phase input end 3 to pass through the straight tube of the T-shaped three-way joint 1 and insert it into the reducing tube 2, the T-shaped three-way joint The branch pipe of 1 is the inflow end 4 of the continuous phase; at the same time, the capillary is inserted into the smaller inner diameter end of the variable diameter tube 2 as the outflow end 5 of the droplet suspension to connect; the dispersed phase and the continuous phase are driven by positive or negative pressure; the dispersed phase passes through The dispersed phase input port 3 breaks through the straight pipe of the T-shaped tee structure 1 and enters the variable diameter pipe 2, and is divided into a group of droplets by the continuous phase flowing in from the continuous phase input port 4 and suspended in the continuous phase. The reducing tube 2 and the droplet suspension outflow port 5 flow out.

US patent application US20140147908A1 discloses a method of cutting liquid droplets by using negative pressure.

The above information is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in the art to a person of ordinary skill in the art. The above patent application text involves the use of positive pressure or negative pressure to realize sampling or transportation, or realize cutting and sampling of liquid droplets in converging pipelines.

However, neither the above-mentioned patent application nor the prior art involves the possibility of sampling and pushing alternately with positive and negative pressures, and at the same time realizes that the liquid sample is wrapped by a medium (usually oil) (i.e. forms the so-called water-in-oil form) and then the sample droplets are processed. Apparatus and method of cutting. At the same time, the device also ensures that redundant samples can be withdrawn from the pipeline, blocking contamination between samples and samples.

In addition, the droplet sampler in the prior art cannot realize the injection of various samples, because in the field of microfluidic chips, the use of microfluidic chips can realize the detection of multiple samples at the same time, such as the common Qualcomm Quantity screening, etc. Usually, a large number of mutants need to be screened at the same time for a certain mutant system. Therefore, if a droplet sampler can be used to obtain different liquid samples and enter the chip one by one for detection, the workload of screening will be greatly saved. At the same time, since the injected liquid samples are usually cell culture fluids, tissue reaction fluids, protein or enzyme action systems, it is also hoped that each sample can be effectively coated and blocked when injecting multiple liquid samples. Thus preventing contamination between samples.

However, there is no such device in the prior art, which can realize the continuous sampling of samples from different systems such as different reaction systems and culture systems without contamination between each other, and at the same time realize the sampling of the obtained samples by using the medium. Wrap and cut.

Based on the problems existing in the above-mentioned prior art and the needs in the field of microfluidics, the object of the present invention is to provide a droplet sampler, especially a droplet sampler used in the field of microfluidics, which can A small amount of liquid sample is transferred from an open system to a closed micro-channel system, especially in the form of a medium-in-liquid sample, such as water-in-oil, to wrap a small amount of liquid sample into a medium, such as oil droplets, and transport it in the micro-channel system.

Another object of the present invention is to provide a method for injecting micro-liquid samples, by using this method, micro-liquid samples can be transferred from an open system to a closed micro-pipeline system, especially with a liquid sample in a medium, such as an oil-in- In the form of water, trace amounts of liquid samples are encapsulated in a medium, such as oil droplets, and transported in a microchannel system.

Utilize the droplet sample injector of the present invention and the method for injecting trace liquid samples, can realize adopting positive and negative pressure alternate sampling, pushing, and realize wrapping liquid sample through medium (usually oil) (that is to form so-called water-in-oil form) A device and a method for finally cutting a sample droplet. At the same time, the device also ensures that redundant samples can be withdrawn from the pipeline, preventing contamination between the samples injected twice and the samples.

Utilizing the liquid drop sampler and the method for injecting trace liquid samples of the present invention, it is possible to realize continuous sampling of liquid samples from different systems such as different reaction systems and culture systems without contamination between each other, and at the same time realize The obtained samples were wrapped with media and cut.

The purpose of the present invention is to be achieved through the following technical solutions.

1. A droplet sampler comprising:

A sample channel, which is used to inhale and transport liquid samples, is connected to a module that provides negative pressure;

A medium channel, which is used to push the medium, is connected to a module that provides positive pressure;

The sample channel and the media channel are in fluid communication.

2. The droplet injector according to item 1, wherein the inner diameter of the sample channel is 10 microns to 5 mm, preferably 50 microns to 2 mm, more preferably 100 microns to 1 mm, further preferably 200 microns to 1 mm 0.6mm.

3. The droplet sampler according to item 1 or 2, wherein the inner diameter of the medium channel is 5 microns to 10 mm, preferably 25 microns to 4 mm, more preferably 50 microns to 2 mm, further preferably 100 Micron ~ 1.2 mm.

4. The droplet sampler according to any one of items 1 to 3, wherein the ratio of the inner diameter of the sample channel to the medium channel (inner diameter of the sample channel/inner diameter of the medium channel) ranges from 1:10 to 10:1 , preferably 1:5 to 5:1, more preferably 1:2 to 2:1, and may be 1:1.

5. The droplet sampler according to any one of items 1 to 4, wherein, the sample channel and the medium channel are formed of hydrophobic materials or coated inside with hydrophobic materials.

6. The droplet sampler according to any one of items 1 to 5, wherein the sample channel communicates directly with the medium channel.

7. The droplet sampler according to any one of items 1 to 6, wherein the sample channel and the medium channel are in fluid communication through a common container.

8. The droplet sampler according to any one of items 1 to 7, wherein the module for supplying negative pressure and the module for supplying positive pressure are plunger pumps.

9. The droplet sampler according to any one of items 1 to 8, wherein the medium is hydrophobic and the liquid sample is hydrophilic.

10. The droplet sampler according to any one of items 1 to 9, wherein the droplet sampler has its sample channel and medium channel filled with medium before starting to use.

11. A method of injecting a trace liquid sample, comprising using a droplet sampler, the droplet sampler comprising:

A sample channel, which is used to inhale and transport liquid samples, is connected to a module that provides negative pressure;

A medium channel, which is used to push the medium, is connected to a module that provides positive pressure;

The sample channel and the medium channel are in fluid communication,

The methods include:

The first step: under the premise that the module providing negative pressure and the module providing positive pressure are closed and the sample channel and medium channel are filled with medium, insert the droplet sampler into the liquid sample to be taken,

Step 2: Open the module that provides negative pressure to draw the liquid sample into the sample channel.

Step 3: Close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step, so that a certain amount of liquid sample is retained in the sample channel, and thus A certain amount of liquid sample retained in the sample channel is coated with the medium.

Step 4: Close the module for positive pressure and keep the module for negative pressure closed, stop pushing the medium, so as to complete the injection of a sample,

Repeat the steps from step 1 to step 4 to complete a new sample injection.

12. The method according to item 11, wherein the primary sample and the new secondary sample are different liquid samples.

13. The method according to item 11 or 12, wherein the droplet sampler is the droplet sampler according to any one of items 1-10.

14. The method according to item 11 or 12, wherein, in the second step, the module providing negative pressure is opened to draw excess liquid sample into the sample channel and make it cover the part where the medium channel directly communicates with the sample channel.

In the third step: close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step, and the excess liquid sample in the sample channel is removed from the sample The channel is pushed out, so that a certain amount of liquid sample is retained in the sample channel, and thus the certain amount of liquid sample retained in the sample channel is coated by the medium.

15. The method according to item 11 or 12, wherein, in the second step, the module providing negative pressure is opened to draw the liquid sample into the sample channel,

In the third step: close the module that provides negative pressure and open the module that provides positive pressure, thereby pushing out the medium from the medium channel to make the medium contact with the liquid sample sucked in the second step, and connect the liquid sample in the sample channel with the sample channel The outer liquid sample is separated such that an amount of liquid sample remains in the sample channel and thus the amount of liquid sample retained in the sample channel is coated with the medium.

As mentioned above, the droplet sample injector in the embodiment of the present invention has a simple structure, and realizes sample injection, cutting, medium wrapping and separation of droplet samples by alternately supplying positive and negative pressures. The droplet sampler does not use valves and the like generally used in the prior art, so its structure is simple. In addition, the droplet sampler of the present invention can wrap, cut and discharge redundant samples for each sample entering the sample channel, so that the samples injected each time can be isolated from each other without mutual contamination and influence, so it can realize Continuously inject multiple samples.

The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer, to the extent that those skilled in the art can implement it according to the contents of the description, and to enable the above and other purposes of the present invention, The features and advantages can be more obvious and understandable, and the specific implementation manners of the present invention are illustrated below for illustration.

Description of drawings

Various other advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings in the description are for the purpose of illustrating preferred embodiments only and are not to be considered as limiting the invention. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to these drawings without creative efforts. Also throughout the drawings, the same reference numerals are used to denote the same parts.

Fig. 1 is a schematic diagram of the droplet injector of the present invention.

Fig. 2(a) is a schematic flow diagram of the liquid droplet injector of the present invention wrapping the droplet with a medium and cutting and pushing it, and Fig. 2(b) is an operation process of processing samples using the liquid droplet sampler of the present invention.

Fig. 3 (a) and (b) two deformation modes of the droplet sampler of the present invention.

Fig. 4 is a schematic diagram of using the droplet sampler of the present invention in a microfluidic sampling device.

Detailed ways

Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and is not limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

Figure 1 shows a schematic diagram of the droplet injector of the present invention. Fig. 1 schematically shows the relationship between the sample channel and the medium channel. As can be seen from Fig. 1, the droplet sampler of the present invention includes: a sample channel, which is used to inhale and deliver a liquid sample, and the sample channel is connected to a module providing negative pressure; a medium channel, which is used to push a medium, The medium channel is connected to a module providing positive pressure, and the sample channel and the medium channel are in fluid communication.

The sample channel and the medium channel provided in the schematic diagram in Figure 1 are directly connected, those skilled in the art can understand that Figure 1 is only schematic, and the communication mode of the sample channel and the medium channel is not limited to the way shown in Figure 1 . The communication mode of the sample channel and the medium channel is fluid communication, that is, the fluid can enter the medium channel from the sample channel and enter the sample channel from the medium channel. In the following, the present invention also provides several variants for realizing the fluid communication between the sample channel and the medium channel. Those skilled in the art can understand that any manner capable of realizing fluid communication is included in the scope of the present invention.

As shown in Figure 1, the sample channel and the medium channel are respectively connected to the module providing negative pressure and the module providing positive pressure. In the present invention, there is no specific limitation on the modules for providing negative pressure and positive pressure, and any means known to those skilled in the art can be implemented, for example, push and suction realized by means such as needle tubes can be listed to provide positive pressure, respectively. Pressure and negative pressure, can also enumerate the pump that can provide positive pressure and negative pressure, because use in the field of microfluidics, the liquid drop sampler of the present invention preferably uses equipment such as plunger pump, syringe pump; Negative pressure gas source pushes the medium to provide; or any other means that can achieve the same function.

In addition, the working time of the positive and negative pressure can be controlled by the switch of the solenoid valve, so that the automatic continuous sampling at the specified time can be realized.

As shown in Fig. 2(a) and (b), a schematic flow chart of injecting liquid samples using the droplet sampler of the present invention is given. As shown in Figure 2(a), before the 1-suction step, the medium channel and the sample channel of the droplet sampler are filled with medium. In the 1-suction step, the module providing negative pressure is opened, and the negative pressure will Excess liquid sample is aspirated into the sample channel, and this liquid sample is brought into fluid communication with the medium channel, as indicated by the arrow in the upper left panel of Figure 2(a), in the case shown in the schematic diagram of Figure 2(a) , the liquid sample is directly in contact with the medium channel, which covers the outlet of the medium channel in contact with the sample channel. In the 2-cutting (separation) step, first close the module that provides negative pressure and open the module that provides positive pressure, at this time the medium in the medium channel is raised and contacted with the excess liquid sample, the liquid sample is cut (the The sample is divided into two parts), and the excess sample is pushed out of the sample channel, as shown by the arrow in the upper right panel of Fig. 2(a). In the step of 3-pushing out, the positive pressure is continuously supplied, and the excess sample is completely pushed out from the sample channel, so that the liquid sample retained in the sample channel is covered by the medium (also can be called a package), and then closed to provide positive pressure and keep closed the module that provides negative pressure, thereby completing the injection of a sample, as shown by the arrow in the lower right figure of Fig. 2(a). In the 4-re-absorption step, open the module providing negative pressure again, inhale new samples, and push forward the samples that have been coated or wrapped by the medium in the previous step. As mentioned above, the steps in the sampling method of the present invention are repeated again, so as to realize the sampling process of a new sample.

The above-mentioned whole process is further shown in Fig. 2(b), and the sample container is also schematically shown in Fig. 2(b), in which the liquid sample to be taken is placed.

As mentioned above, the method for injecting a trace liquid sample of the present invention comprises the following steps:

The first step: under the premise that the module providing negative pressure and the module providing positive pressure are closed and the sample channel and medium channel are filled with medium, insert the droplet sampler into the liquid sample to be taken (as shown in Figure 2(b) shown in the leftmost figure in ),

The second step: open the module that provides negative pressure to suck the liquid sample into the sample channel (as shown in the second figure from the left in Figure 2(b),

Step 3: Close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step, so that a certain amount of liquid sample is retained in the sample channel, and thus A certain amount of liquid sample retained in the sample channel is covered by the medium (as shown in the figure in the middle of Figure 2 (b)),

Step 4: Close the module for positive pressure and keep the module for negative pressure closed, stop pushing the medium, so as to complete the injection of a sample (as shown in the second picture on the right of Figure 2(b)),

Repeat the steps from the first step to the fourth step to complete a new sample injection (as shown in the rightmost figure in Fig. 2(b)).

In the above method, a certain amount of liquid sample refers to the amount of sample to be used in the subsequent micro-channel system, for example, the amount of sample to be detected by the detector on the chip in the micro-channel system, or the amount of sample that needs to be detected in the micro-channel system. The amount of sample that needs to be processed in the microchannel system, or the amount of sample that is drawn into the microchannel system for contact or reaction with other samples in the microchannel system.

There is no specific limit to the certain amount, and those skilled in the art know how to select an appropriate amount according to the subsequent sample processing or detection, for example, it can be listed: 1 nanoliter to 20 microliters, 2 nanoliters to 15 microliters, 5 nanoliters to 15 microliters, liter to 10 microliters, 10 nanoliters to 9 microliters, 50 nanoliters to 5 microliters, etc., for example, 20 microliters, 15 microliters, 10 microliters, 9 microliters, 8 microliters, 7 microliters Liter, 6 microliter, 5 microliter, 4 microliter, 3 microliter, 2 microliter, 1.5 microliter, 1 microliter, 900 nanoliter, 800 nanoliter, 700 nanoliter, 600 nanoliter, 500 nanoliter, 400 nanoliters, 300 nanoliters, 200 nanoliters, 100 nanoliters, 50 nanoliters, 30 nanoliters, 10 nanoliters, 5 nanoliters, 1 nanoliter, etc.

According to the above description, it can be known that the liquid sample injector of the present invention can effectively realize the liquid sample injection, and utilize the medium to cut the liquid sample and push out the redundant liquid sample (that is, the sample is divided into two parts and reserved for subsequent use). A certain amount of sample, or separate the sample near the sample channel from a certain amount of sample for subsequent use), and then use the medium to wrap the remaining liquid sample to be operated, thereby completing a sample injection. With such a device and method, different liquid samples can be continuously injected, and each liquid sample can be isolated from each other without interfering with each other.

After completing one or one stage of sample injection, close the inlet port and open the outlet port to adjust the position of the sample droplet in the micro-pipeline system through positive pressure; if another micro-pipeline system is connected to the outlet port, it can be passed through Continuous positive pressure pushes to transfer the sample droplets into the system.

In addition, the inlet section of the sample channel can be closed when the sample is not being injected. The closing method can be used, but not limited to, method 1: sleeve type, that is, a cap that can be placed on the inlet end is used, and the cap is buckled on the inlet end. Closing on the top; method 2: pressure type, making a soft, such as rubber pad, and pressing it on the inlet end to achieve closure.

Fig. 1 and Fig. 2 only schematically show the structure of the droplet sampler of the present invention and the flow chart of its operation. The container used to hold the sample in Fig. 2(b) can be the open system in the present invention as mentioned above, such as various forms such as 96-well plate, centrifuge tube, flask, and sample tube. The liquid sample can also be samples in various liquid forms in the art, such as aqueous solution of chemical reagents, cell culture fluid, cell reaction fluid, enzyme reaction fluid, protein solution, DNA, RNA and other deoxynucleic acid or nucleic acid solution, etc.

In the droplet sampler of the present invention, there is no specific limitation on the size of the droplet sampler, but it is preferably a size that helps to realize the medium-encapsulated liquid sample. For example, the inner diameter of the sample channel is 10 micrometers to 5 millimeters, preferably 50 micrometers to 2 millimeters, more preferably 100 micrometers to 1 millimeter, and even more preferably 200 micrometers to 0.6 millimeters. For example, the inner diameter of the sample channel can be 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns Micron, 700 micron, 800 micron, 900 micron, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm. The above specific numerical values are merely examples, and may be any specific numerical values ranging from 10 microns to 5 mm.

For example, the inner diameter of the medium channel is 5 micrometers to 10 millimeters, preferably 25 micrometers to 4 millimeters, more preferably 50 micrometers to 2 millimeters, and even more preferably 100 micrometers to 1.2 millimeters. For example, the inner diameter of the media channel can be 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns Micron, 200 micron, 300 micron, 400 micron, 500 micron, 600 micron, 700 micron, 800 micron, 900 micron, 1 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm. The above specific numerical values are merely examples, and may be any specific numerical values in the range of 5 microns to 10 mm.

Further, there is no specific limitation on the relationship of the inner diameter between the sample channel and the medium channel, as long as it is helpful to realize the ratio of the medium wrapping the liquid sample, such as the ratio of the inner diameter of the sample channel to the medium channel (sample channel inner diameter/medium Channel inner diameter) ranges from 1:10 to 10:1, preferably from 1:5 to 5:1, more preferably from 1:2 to 2:1, and can be, for example, 1:1.

In the above, the inner diameter referred to in the present invention is the diameter of the inner channel of the medium channel or the sample channel.

In the present invention, as mentioned above, the liquid sample can be an aqueous solution of chemical reagents, cell culture fluid, cell reaction solution, enzyme reaction solution, protein solution, DNA, RNA and other deoxynucleic acid or nucleic acid solutions, etc., in this The liquid sample in the invention is preferably a hydrophilic or aqueous sample.

The medium used in the present invention is usually a lipophilic medium, and various oily substances generally used in this field can be used. Such as mineral oil, low temperature paraffin, vegetable oil.

In the present invention, there is no limitation on the material of the droplet injector, as long as it is a material that can realize the medium encapsulation of the liquid sample through the operation of the present invention. Preferably, the sample channel and the medium channel are formed of hydrophobic materials or their interiors are covered with hydrophobic materials. Hydrophobic materials include polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), polyethylene (PE), polypropylene (PP), polystyrene (PS) and other hydrophobic organic polymer materials. It can be stainless steel, titanium alloy, copper, platinum, gold and other metal materials.

In a specific embodiment of the droplet sampler involved in the present invention, its sample channel is directly connected with the medium channel. Specifically, it can be referred to the direct communication through the tee shown in Figure 2(a), so that when the medium is used to cut the liquid sample, the medium pushed out by positive pressure can directly contact the excess liquid sample sucked and It cuts and pushes out the excess liquid sample further, enclosing the sample desired for subsequent manipulation or testing.

In the method for injecting a trace amount of liquid sample using this specific embodiment, in the second step, open the module providing negative pressure to draw excess liquid sample into the sample channel and make it cover the position where the medium channel is directly connected to the sample channel ( The liquid sample is directly in contact with the medium channel, which covers the outlet of the medium channel in contact with the sample channel), in the third step: close the module that provides negative pressure and open the module that provides positive pressure, thereby pushing out the medium from the medium channel to use The medium is in contact with the liquid sample sucked in the second step, and the excess liquid sample in the sample channel is pushed out from the sample channel, so that a certain amount of liquid sample is retained in the sample channel, and thus a certain amount of liquid sample retained in the sample channel covered by medium.

In another specific embodiment of the droplet sampler involved in the present invention, the sample channel and the medium channel are in fluid communication through a common container. Specifically, reference may be made to the two exemplary implementations shown in Fig. 3(a) and (b).

In the method for injecting trace liquid samples using this specific embodiment, in the second step, open the module that provides negative pressure to draw the liquid sample into the sample channel, and in the third step: close the module that provides negative pressure and open the module that provides A module of positive pressure, thereby pushing out the medium from the medium channel to make the medium contact with the liquid sample sucked in the second step (for example, contacting at the sample channel port, such as shown in Figures 3 (a) and 3 (b)), and the sample The liquid sample in the channel is separated from the liquid sample outside the sample channel (for example, near the sample channel port or attached to the liquid sample outside the sample channel), so that a certain amount of liquid sample is retained in the sample channel, and thus the remaining liquid sample in the sample channel A certain amount of liquid sample is coated with the medium.

Specifically, in Figure 3(a), the inner diameter of the sample channel is smaller than the inner diameter of the medium channel, and the medium channel and the sample channel are in the form of a sleeve, that is, the medium channel is located on the outside of the sample channel. The container realizes that the medium channel is in fluid communication with the sample channel. As shown in FIG. 3( a ), by filling the lower container with medium, and inserting the inlets of the medium channel and the sample channel into the medium-filled container, fluid communication between the medium channel and the sample channel can be achieved.

Therefore, when using this liquid sampler to realize sample injection, firstly, in the first step, under the premise that the module providing negative pressure and the module providing positive pressure are closed and the sample channel and medium channel are filled with medium, the The drop sample injector shown in (a) is inserted into the liquid sample to be taken. At this time, the container filled with the medium together with the medium channel and the sample channel is inserted into the liquid sample to be taken. In the second step, the module that provides negative pressure is opened to suck the liquid sample through the container filled with the medium and enter the sample channel. At this time, the end of the liquid sample is located at the inlet of the sample channel, which can be in fluid contact with the medium. In the third step: close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step (mainly the sample is located at the end of the sample channel inlet), And the liquid sample in the sample channel is separated from the liquid sample outside the sample channel, so that a certain amount of liquid sample remains in the sample channel, and thus the certain amount of liquid sample retained in the sample channel is covered by the medium. In this embodiment, the liquid sample outside the sample channel is usually located outside and near the inlet of the sample channel, or is a sample located outside the sample channel. The last fourth step is to close the module for positive pressure and keep the module for negative pressure closed, stop pushing the medium, so as to complete the injection of a sample. Repeat the steps from step 1 to step 4 to complete a new sample injection.

In the specific embodiment shown in the above-mentioned Fig. 3 (a), the container filled with the medium can be a tapered container such as the tip of a pipette gun, or a syringe needle, or any other similar container, as long as it can When it is inserted into the liquid sample together with the sample channel and the medium channel, it only needs to be a container capable of sucking the liquid sample into the sample channel through the container.

In addition, as described above, the container containing the liquid sample may be various open systems such as 96-well plate, test tube, flask, Petri dish, and the like. In addition, in the embodiment given in Fig. 3 (a), the inner diameter of the medium channel is greater than the inner diameter of the sample channel, those skilled in the art can understand that, in the opposite way, that is, the inner diameter of the medium channel is smaller than the inner diameter of the sample channel, the medium The embodiment in which the channel is located inside the sample channel is also possible, as long as the method for injecting a small amount of liquid sample described in the present invention can be realized. In the present invention, preferably, the inner diameter of the medium channel is larger than the inner diameter of the sample channel, so as to better realize the cutting of redundant samples.

Further, as shown in Figure 3 (a), the sample inlet of the sample channel stretches out of the medium channel, and those skilled in the art can also understand that the sample inlet of the sample channel and the medium inlet of the medium channel can be In parallel, the sample inlet of the sample channel may also be located in the medium channel, as long as the method for injecting a small amount of liquid sample described in the present invention can be realized. In the present invention, it is preferable that the length of the sample channel is longer than that of the medium channel, so that cutting of excess samples can be better realized.

In addition, Fig. 3 (b) also shows another form in this embodiment, that is, the sample channel and the medium channel are not realized in the form of sleeves, but two parallel channels. The morphology shown in Figure 3(a) is consistent. At this time, the sample method described in the present invention is to inject a micro-volume liquid sample. The inner diameters of the channel and the medium channel may be the same or different, as long as the method for injecting a small amount of liquid sample described in the present invention can be realized. In addition, the sample inlet of the sample channel and the medium inlet of the medium channel may be parallel or non-parallel, as long as the method for injecting trace liquid samples described in the present invention can be realized. In the present invention, it is preferable that the length of the sample channel is longer than that of the medium channel, so that cutting of excess samples can be better achieved.

When the droplet injector of the present invention is used in the field of microfluidics, its operation schematic diagram is shown in FIG. 4 . In the first step, under the premise that the module providing negative pressure and the module providing positive pressure are closed and the sample channel and medium channel are filled with medium, insert the droplet sampler into the liquid sample to be taken, and then in the second step, Open the module that provides negative pressure to draw the liquid sample into the sample channel, then in the third step, close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium and the liquid sucked in the second step The sample is contacted, so that a certain amount of liquid sample is retained in the sample channel, and thus a certain amount of liquid sample retained in the sample channel is covered by the medium, and then in the fourth step, the module for positive pressure is closed and kept closed to provide The module with negative pressure stops pushing the medium, so as to complete the injection of a sample.

Then, repeat the steps from the first step to the fourth step, so as to complete a new sample injection.

The liquid sample coated and inhaled by the medium is gradually pushed forward with the next injection, and pushed into the micro-pipeline system for subsequent detection and processing, and can be discharged from the sample outlet after the detection is completed. Thus, by repeatedly opening and closing the positive pressure and negative pressure modules, the sample can enter the package and enter the micro-pipeline system for detection.

In addition, a closure cap is also drawn in FIG. 4 , which can close the sample inlet when not used for sample injection, thereby preventing contamination of the sample channel. In addition, after the liquid sample is detected or processed, when it needs to be transferred or the droplet is discarded, it is necessary to close the closed cover, and then open the positive pressure to push out or transfer the droplet sample, that is, to exclude the droplet sample from the entire system.

In addition, the liquid drop sampler of the present invention can sample different samples. After the first liquid sample is injected, the pipeline near the sample inlet can be cleaned by wiping, rinsing, etc., and then the second time When injecting samples, the droplet injector can be inserted into different sample liquids for sampling, for example, for 96-well plates, or multi-sample systems, one droplet injector can be used to enter different samples at the same time, so that it is simple The detection of multi-system samples can be effectively realized, and the samples entering the sample channel will not pollute and affect each other during the process of transporting to the micro-pipeline system because they are separated by the medium.

Figure 4 only schematically depicts the schematic diagram of the combination of the droplet sampler of the present invention into the whole system, and those skilled in the art can understand that all the specific implementations of the droplet sampler of the present invention can be combined To the microfluidic system, it is used to send the droplet sample into the micropipeline system.

In the present invention, the micro-pipeline system can be a microfluidic chip, and the samples transported to the micro-pipeline system can be processed and detected in the microfluidic chip. In addition, the micropipe system also includes other pipe systems used in the field of microfluidic control known to those skilled in the art, such as capillary tubes and the like.

The present application accepts various modifications and alternative forms, and specific embodiments have been shown by way of example in the drawings and have been described in detail in the present application. However, it is not intended that the application be limited to the particular form disclosed. On the contrary, the application is intended to cover all modifications, equivalents, and alternatives coming within the scope of the application as defined by the appended claims and their legal equivalents.

The numerical ranges enumerated in the present invention include the data of the two endpoints of the numerical range, and also include each specific numerical value in the numerical range, and the numerical values can be combined with the endpoints to form a new small range.

Claims (13)

1. A droplet sampler comprising: A sample channel, which is used to inhale and transport liquid samples, is connected to a module that provides negative pressure; A medium channel, which is used to push the medium, is connected to a module that provides positive pressure; The sample channel and the media channel are in fluid communication. 2. The droplet sample injector according to claim 1, wherein the inner diameter of the sample channel is 10 microns to 5 mm, preferably 50 microns to 2 mm, more preferably 100 microns to 1 mm, more preferably 200 microns ~0.6 mm. 3. The droplet sampler according to claim 1 or 2, wherein the inner diameter of the medium channel is 5 microns to 10 mm, preferably 25 microns to 4 mm, more preferably 50 microns to 2 mm, more preferably 100 microns to 1.2 mm. 4. The droplet sampler according to any one of claims 1 to 3, wherein the ratio of the inner diameter of the sample channel to the medium channel (sample channel inner diameter/medium channel inner diameter) ranges from 1:10 to 10: 1, preferably 1:5 to 5:1, more preferably 1:2 to 2:1. 5. The droplet sampler according to any one of claims 1-4, wherein the sample channel and the medium channel are formed of hydrophobic materials or coated with hydrophobic materials. 6. The droplet sampler according to any one of claims 1-5, wherein the sample channel is in direct communication with the medium channel. 7. The droplet sampler according to any one of claims 1-6, wherein the sample channel and the medium channel are in fluid communication through a common container. 8. The droplet sampler according to any one of claims 1 to 7, wherein the medium is hydrophobic and the liquid sample is hydrophilic. 9. A method of injecting a trace liquid sample, comprising using a droplet sampler, the droplet sampler comprising: A sample channel, which is used to inhale and transport liquid samples, is connected to a module that provides negative pressure; A medium channel, which is used to push the medium, is connected to a module that provides positive pressure; The sample channel and the medium channel are in fluid communication, The methods include: The first step: under the premise that the module providing negative pressure and the module providing positive pressure are closed and the sample channel and medium channel are filled with medium, insert the droplet sampler into the liquid sample to be taken, Step 2: Open the module that provides negative pressure to draw the liquid sample into the sample channel, Step 3: Close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step, so that a certain amount of liquid sample is retained in the sample channel, and thus A certain amount of liquid sample retained in the sample channel is covered by the medium, Step 4: Close the module for positive pressure and keep the module for negative pressure closed, stop pushing the medium, so as to complete the injection of a sample, Repeat the steps from step 1 to step 4 to complete a new sample injection. 10. The method of claim 9, wherein the primary sample and the new secondary sample are different liquid samples. 11. The method according to claim 9 or 10, wherein the droplet sampler is a droplet sampler according to any one of claims 1-8. 12. The method according to claim 9 or 10, wherein, in the second step, the module providing negative pressure is opened to draw excess liquid sample into the sample channel and make it cover the part where the medium channel directly communicates with the sample channel. In the third step: close the module that provides negative pressure and open the module that provides positive pressure, so that the medium is pushed out from the medium channel to make the medium contact with the liquid sample sucked in the second step, and the excess liquid sample in the sample channel is removed from the sample The channel is pushed out, so that a certain amount of liquid sample is retained in the sample channel, and thus the certain amount of liquid sample retained in the sample channel is coated by the medium. 13. The method according to claim 9 or 10, wherein, in the second step, the module that provides negative pressure is opened to draw the liquid sample into the sample channel, In the third step: close the module that provides negative pressure and open the module that provides positive pressure, thereby pushing out the medium from the medium channel to make the medium contact with the liquid sample sucked in the second step, and connect the liquid sample in the sample channel with the sample channel The outer liquid sample is separated such that an amount of liquid sample remains in the sample channel and thus the amount of liquid sample retained in the sample channel is coated with the medium.