A double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions

Abstract

The present invention provides a double-chamber centrifuge tube that integrates the functions of suspension separation and supernatant extraction. The partition and the one-way valve are used to separate the liquid area inside the centrifuge tube, and the centrifugal force is used as the switch for opening and closing the one-way valve. The method is extremely efficient, fast and pure when it is used in occasions where supernatant extraction is required.

Description

Technical Field

[0001] The invention relates to the application field of centrifugal force technology, and in particular to a double-cavity centrifuge tube integrating suspension separation and supernatant extraction. Background Art

[0002] A centrifuge is a machine that uses centrifugal force to separate components in a liquid and solid particles or a mixture of liquid and liquid. The size of the centrifugal force is determined by the rotation speed, rotation radius and mass of the substance. Centrifuges are widely used in chemical engineering, petroleum, food processing, pharmaceuticals, mineral processing engineering, carbon, water treatment, nuclear energy industry and shipping. The sample suspension is placed in a centrifuge tube and rotated at high speed. Due to the huge centrifugal force, the suspended tiny particles (such as organelles, biomacromolecule precipitation, etc.) settle at a certain speed and are separated from the solution.

[0003] The centrifugal extraction integrated centrifuge tube can bring centrifugal technology into a new stage. Different from the traditional supernatant extraction (first centrifugal precipitation and then extraction outside), the entire operation of supernatant generation and extraction can be completed in the centrifuge tube. This structure based on the centrifuge tube design has the following advantages: since the entire process is inside a relatively closed centrifuge tube, the purity of the supernatant is well guaranteed; since it is an integrated separation and extraction operation, it can greatly reduce the manual workload and simplify the procedure. Summary of the invention

[0004] The purpose of the present invention is to develop a multifunctional double-chamber centrifuge tube for supernatant extraction and a method for supernatant extraction using the centrifuge tube structure, specifically involving the whole process of adding a sample suspension, separating the suspension by centrifugal force, opening a baffle by centrifugal force, and allowing the supernatant to flow into a collection chamber after the baffle is opened.

[0005] The double-chamber centrifuge tube utilizes a baffle installed in the middle of the partition, an elastic structure and regional control of the sample solution to realize the opening and closing control of the one-way valve, complete the extraction after the supernatant is separated, and completes the process from the sample suspension to the stratified solution and then to the collection of the supernatant through the comprehensive regulation of the centrifugal force and the direction of the elastic one-way valve.

[0006] The double-chamber centrifuge tube is divided into a three-layer structure, such as Figure 1 As shown, there are 1 sample chamber, 2 collection chamber and 3 partitions. The partition layer is located between the sample chamber and the collection chamber and separates the two chambers. 4 elastic one-way valves include three parts: a spring, a mass block at the end of the spring and a baffle (with a small thickness and gravity is ignored). The opening and closing of the baffle is controlled by the elastic force, the gravity of the mass block and the centrifugal force.

[0007] Beneficial Effects

[0008] 1. The present invention can simplify the operation steps of supernatant extraction through the design of the centrifuge tube structure, greatly speeding up the process of on-site sampling and collection;

[0009] 2. The process of collecting the supernatant through the centrifuge tube is carried out in the process of closing the centrifuge tube, which can avoid contamination and minimize contact with the outside world;

[0010] 3. The process of simplifying the process also reduces the use of other equipment besides the centrifuge, reduces equipment requirements, and also reduces personnel costs and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional structure of a centrifuge tube placed vertically when no sample is added, 1 is a sample chamber, 2 is a collection chamber, 3 is a partition, which separates the sample chamber and the collection chamber from the middle position, and 4 is an elastic one-way valve, which mainly includes an elastic structure, a baffle and a mass block.

[0012] Figure 2 It is the loading state. At this time, the sample suspension is loaded into the sample chamber, and the end of the baffle is acted upon by elastic force and hydraulic pressure. The elastic force pushes the baffle to the right against the partition, and the hydraulic pressure pushes the baffle to the left to separate from the partition. By ensuring that the elastic force is greater than the hydraulic pressure, the elastic one-way valve remains closed and the suspension will not penetrate into the collection chamber.

[0013] Figure 3 The centrifuge tube is in an inclined state when it is inserted into the centrifuge but centrifugation has not yet started, with the sample chamber on top and the collection chamber on the bottom. At this time, the sample suspension is placed in the inclined sample chamber. Because of the inclination angle, the hydraulic depth at the baffle becomes shallower, the pressure decreases, and the elastic force remains unchanged. The pressure is still less than the elastic force, ensuring that the elastic force perpendicular to the direction of the baffle is greater than the hydraulic pressure and the gravity component of the mass block at the end of the baffle. The elastic one-way valve is still closed.

[0014] Figure 4 After the centrifuge is inserted with the sample chamber on top and the collection chamber on the bottom, the centrifugation ends and the suspension is separated. During the centrifugation process, the centrifugal force is to the right in the same direction as the elastic force, so the combined force with gravity is still to the right, and the elastic one-way valve remains closed.

[0015] Figure 5 To complete the separation of the suspension and after the solution is layered, take out the centrifuge tube, rotate it 180° and reinsert it into the centrifuge so that the sample chamber is at the bottom and the collection chamber is at the top. At this time, the hydraulic pressure on the baffle is less than the elastic force, and the direction of the gravity component of the mass block is the same as the direction of the elastic force, so the one-way valve is still closed.

[0016] Figure 6 This is the state after the second centrifugal speed stabilizes. At this time, the speed is greater than the threshold, and the combined force of the centrifugal force and pressure on the baffle is much greater than the combined force of the elastic force and the gravity of the mass block, causing the one-way valve to open, and the supernatant flows into the collection chamber until the liquid level in the sample chamber is consistent with the height of the elastic one-way valve.

[0017] Figure 7 This is the state where the centrifuge tube has not been taken out of the centrifuge after the second centrifugation is completed. At this time, the hydraulic pressure no longer acts on the elastic one-way valve, and only the elastic force closes the one-way valve.

[0018] Figure 8 After the centrifuge tube is taken out of the centrifuge, it is placed vertically. The hydraulic pressure at this time is lower than the hydraulic pressure when it is filled with samples, so it is still lower than the elastic force exerted on the baffle, and the elastic one-way valve is closed.

[0019] Through the completion of these five states in sequence, the supernatant added with the suspension reagent is extracted, wherein 5 is the suspension sample, 6 is the supernatant, and 7 is the sedimentation liquid.

[0020] Fig. 9 The switch structures of several one-way valves are shown in the following examples. (a) The one-way valve is constructed by compressing a right-angle spring sheet to apply pressure as the elastic force of the baffle. In this case, the one-way valve with an elastic structure is composed of a spring sheet. (b) The one-way valve is constructed by folding and bending the spring sheet to apply pressure as the elastic force of the baffle. The elastic structure is composed of a spring sheet and a bending structure. (c) The one-way valve is constructed by directly using a spring to apply pressure as the elastic force of the baffle. The elastic structure is composed of a spring and a baffle.

[0021] Parameter formula for force analysis of elastic check valve structure (taking mass block as analysis object)

[0022] F elastic > F pressure

[0023] Ftotal = Fpressure' + Gcosθ

[0024] F-bounce > F-close

[0025] F from>F elastic sinθ+Gcosθsinθ-F pressure'sinθ

[0026] P = ρgH

[0027] Fpressure=P*S, Fpressure' = ρgh, G=mg

[0028] where ρsample is the sample density,

[0029] θ is the angle between the centrifuge tube and the horizontal plane,

[0030] S is the area of ​​the baffle on the one-way valve,

[0031] g is the acceleration due to gravity,

[0032] m is the mass of the mass block at the end of the one-way valve,

[0033] H is the distance from the spring valve to the centrifuge tube cover

[0034] h is the actual height of the water pressure when calculating the inclination angle h = Hsin θ

[0035] F>>100G

[0036] Then 100mg> Fb> Fpressure=PS=ρgHS and 100mg> Fb> Fpressure' +Gcosθ=ρgHSsin θ+mgcosθ

[0037] Algebraic formula for force analysis of elastic check valve structure

[0038] The structural parameters of the designed centrifuge tube are as follows:

[0039] The capacity is 10ml, the effective length is 10cm, and the baffle area S of the one-way valve is 2mm*2mm

[0040] When the tank is filled with liquid, the hydraulic pressure in the middle of the baffle (taking blood as an example) is as follows:

[0041] P = ρgH = 1.05 g / cm 3 *9.8N / kg *5cm=0.05145N / cm 2

[0042] F pressure = P*S = P*0.04cm 2 =0.000206N

[0043] Where ρ is the sample density, g is the acceleration due to gravity, and H is the distance from the one-way valve to the centrifuge tube cover.

[0044] When the centrifuge tube is inserted into the centrifuge and forms an angle θ with the horizontal plane,

[0045] Fpressure' = Fpressure sinθ

[0046] As long as the elastic force> 0.000206N, the Figure 2 The accuracy of the force analysis mentioned.

[0047] Assuming that the mass block at the end of the one-way valve is an iron sphere with a diameter of 2 mm, its gravity

[0048] G=mg=ρIron V ball g=7.9mg / mm 3 *4 / 3*Π*(1mm) 3 *9.8N / kg=0.000324N

[0049] According to Figure 3 Fclose = Fpressure + Gcosθ, Fspring>Fclose, Fspring>0.00053N

[0050] Figure 6 When the threshold speed is reached, F>>100G, F>F. It is easy to understand that the centrifugal force analysis meets the conditions.

[0051] In summary, the design is established when 0.324N>Fspring>0.00053N is guaranteed.

[0052] Fig. 9 The switch structures of several one-way valves are shown in the figure. (a) is to apply pressure as the elastic force of the baffle by compressing the right-angle spring sheet. In this case, the one-way valve with the elastic structure is composed of spring sheets; (b) is to apply pressure as the elastic force of the baffle by folding and bending the spring sheet. The elastic structure is composed of spring sheets and bending structures; (c) is to directly use the spring to apply pressure as the elastic force of the baffle. The elastic structure is composed of springs and baffles. A part of the spring sheet can be used as a baffle, and the bottom end of the spring is connected to a smooth baffle to seal the valve. 8 is a spring sheet, 9 is a spring, and 10 is a baffle. Specific embodiment:

[0054] According to the present invention, a double-chamber centrifuge tube integrating suspension separation and supernatant extraction is designed, with a capacity of 10ml, an effective length of 10cm, a baffle area S on a one-way valve of 2mm*2mm, and a spring sheet acting on the baffle with an elastic force of 0.1N. The sample chamber is filled with human blood added with anticoagulant, the sample chamber of the centrifuge tube is on the top, the collection chamber is on the bottom, and the tube cover is inserted into a centrifuge with a 45° fixed-angle rotor inward. At this time, the centrifuge tube is 45° to the horizontal plane and the rotating shaft. The centrifuge used is a Xiangyi H1650 desktop high-speed centrifuge, with an angular rotor aperture of 16.5mm and a depth of 76mm. Cover the rotor cover and the centrifuge cover, set the speed to 10000rpm, centrifuge for 10 minutes, then open the centrifuge and the rotor cover, rotate the centrifuge tube 180°, so that the sample chamber is on the bottom and the collection chamber is on the top, cover the rotor and the centrifuge, keep the speed unchanged and continue to centrifuge for 10 minutes, and the serum of human blood can be separated and collected.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions, comprising a centrifuge tube body, characterized in that: The invention comprises a partition and an elastic one-way valve, wherein the partition longitudinally divides the centrifugal tube cavity into a sample cavity and a supernatant collection cavity, the elastic one-way valve comprises a separation hole, a baffle, a mass block, and an elastic structure, the separation hole is arranged on the partition, the baffle covers the separation hole on the supernatant collection cavity side, the elastic structure is fixed to the inner wall of the centrifuge tube or the partition, the elastic force of the elastic structure points to the sample cavity side, the mass block is placed on the baffle, the elastic force of the elastic structure applied to the baffle presses the baffle on the separation hole to close it, the double-cavity centrifuge tube is inserted into the fixed-angle rotor of a centrifuge, and centrifuged when the sample cavity is away from one side of the centrifuge shaft and the supernatant collection cavity is close to one side of the centrifuge shaft, the centrifugal force applied to the mass block and the baffle points to the sample cavity side, the elastic force of the elastic structure applied to the mass block and the baffle points to the sample cavity side, The baffle is pressed against the partition, the elastic one-way valve remains closed, and the suspension is separated by centrifugation; when the sample chamber is close to the centrifuge shaft and the supernatant collection chamber is far from the centrifuge shaft, the centrifugal force exerted on the mass block and the baffle is directed to the supernatant collection chamber, and the elastic force of the elastic structure exerted on the mass block and the baffle is directed to the sample chamber. When the rotation speed is greater than a threshold, the force state of the mass block and the baffle of the elastic one-way valve is as follows: the resultant force toward the supernatant collection chamber is greater than the resultant force toward the sample chamber, the baffle of the elastic one-way valve will be separated from the partition, the separation hole will be opened, and the supernatant in the sample chamber will enter the supernatant collection chamber; described with reference to the state of the centrifuge tube being placed upright, the cross-sectional area of ​​the supernatant collection chamber is 2-3 times that of the sample chamber; the baffle is curved, the sample chamber is set to be thick at the top and thin at the bottom, and the supernatant collection chamber is set to be thin at the top and thick at the bottom.

2. The double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to claim 1, characterized in that: The elastic force of the elastic structure is sufficient to overcome the external force exerted on the baffle of the elastic valve in a static state and a transport state, so that the suspension in the sample chamber cannot enter the supernatant collection chamber.

3. The double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to claim 1, characterized in that: According to the ratio of solid to liquid in the suspension separated by the separation hole, the separation hole is arranged above the solid-liquid interface formed after centrifugal separation.

4. The double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to claim 1, characterized in that: The separation hole is set at a position half the height of the depth of the sample to be processed.

5. The double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to claim 1, characterized in that: The baffle is fixed on the partition away from the bottom of the centrifuge tube, and the baffle is pressed on the separation hole by the elastic force of the baffle relative to the partition, and no elastic structure is provided separately.

6. A double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to any one of claims 1 to 4, characterized in that: The suspension is blood.

7. The double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to claim 6, characterized in that: The elastic force structure applies pressure as the elastic force of the baffle by means of a strip spring sheet, or applies pressure as the elastic force of the baffle by means of compression of a right-angle spring sheet, or applies pressure as the elastic force of the baffle by means of a folded and bent spring sheet, or directly applies pressure as the elastic force of the baffle by means of a spring, and the side of the baffle facing the partition is smooth.

8. A method for using a double-chamber centrifuge tube integrating suspension separation and supernatant extraction functions according to any one of claims 1 to 7, the method comprising the following steps: (1) injecting the suspension sample into the sample chamber; (2) inserting the double-chamber centrifuge tube into a fixed-angle rotor of a centrifuge, with the sample chamber away from the centrifuge shaft and the supernatant collection chamber close to the centrifuge shaft, and centrifuging to separate the suspension into layers; (3) After centrifuging to separate the suspension, the double-chamber centrifuge tube is rotated so that the sample chamber is on the side close to the centrifuge shaft and the supernatant collection chamber is on the side away from the centrifuge shaft, and centrifuged until the rotation speed is greater than a threshold value. The threshold value refers to the rotation speed at which the force state of the mass block and the baffle of the elastic one-way valve is such that the resultant force in the direction of the supernatant collection chamber is greater than the resultant force in the direction of the sample chamber, and the baffle of the elastic one-way valve is separated from the partition. At this time, the separation hole is opened, and the supernatant in the sample chamber enters the supernatant collection chamber; (4) Aspirate the supernatant in the supernatant collection chamber to complete the separation of the suspension and the extraction of the supernatant.

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