Ultrafiltration centrifuge tube with high protein recovery rate and ultrafiltration membrane connecting and fixing method thereof

Abstract

The invention discloses an ultrafiltration centrifuge tube with high protein recovery rate and an ultrafiltration membrane connecting and fixing method thereof, the ultrafiltration centrifuge tube comprises an outer tube and an inner tube, the inner tube is provided with a filtering part, and an ultrafiltration membrane is adhered to the filtering part through glue dispensing; the parameters of the dispensing bonding are as follows: an acrylate structural adhesive is adopted as glue, an LED light source is used for curing, and the dispensing amount is 0.0162-0.0168 g; the parameters of dispensing trial preparation are as follows: the pressure is 0.02 kgf / cm < 2 >, the glue outlet speed is 0.1 turn / s, the back suction speed is 0.15 turn / s, the moving speed is 20mm / s, the aperture of a needle head is 0.38 mm, and the dispensing speed is between 15% and 30%. According to the invention, the adhesive residue after adhesive dispensing and bonding is extremely low, the adhesive overflow is avoided, the adhesive dispensing surface is uniform and complete, the bonding strength is high, and the ultrafiltration centrifugal tube achieves a higher protein recovery rate when being used in a high-speed centrifugal machine.

Description

Technical Field

[0001] The invention relates to the technical field of ultrafiltration centrifuge tubes, and in particular to an ultrafiltration centrifuge tube with high protein recovery rate and a method for connecting and fixing an ultrafiltration membrane thereof. Background Art

[0002] Ultrafiltration centrifuge tubes have a rapid ultrafiltration function, can achieve a high concentration factor, and are easy to recover from diluents and complex sample combinations. Therefore, they are widely used in the field of biofiltration. Ultrafiltration centrifuge tubes are mainly used to concentrate biological samples containing antigens, antibodies, enzymes, nucleic acids (single or double strain DNA / RNA samples), microorganisms, eluates, and purified samples.

[0003] There are many structural forms of ultrafiltration centrifuge tubes. For example, patent CN101745439A discloses an ultrafiltration centrifuge tube, including an outer tube, a support sleeve, an inner tube, and an ultrafiltration membrane. The inner tube includes a liquid-filling part and a filter part that are connected. The liquid-filling part is mounted on the support sleeve and is used to hold the filtered raw liquid. The filter part is inserted into the through hole and abuts against the inner wall of the through hole. The filter part is provided with a filter hole on the side abutting against the through hole; and an ultrafiltration membrane is provided in the accommodating cavity for blocking the filter hole. For another example, patent CN222076318U discloses an ultrafiltration centrifuge tube, including an outer tube, a tube cover is screwed on the opening of the outer tube, a concentrator tube is installed in the outer tube, the concentrator tube includes a tube body, filter plates are provided on both sides of the lower end of the tube body, an ultrafiltration membrane is provided on the inner side of the filter plate, and a plurality of small holes are provided at the lower end of the filter plate.

[0004] Existing ultrafiltration centrifuge tubes usually include an outer tube and an inner tube, the inner tube is provided with a filter part, and the filter part is provided with an ultrafiltration membrane. The inner tube is usually an injection molded part, so the integrity of the connection between the ultrafiltration membrane and the injection molded part has a decisive influence on the core performance of the ultrafiltration centrifuge tube product. Existing technologies for connecting polymer membranes to injection molded parts include: ultrasonic welding technology and hot melt welding technology. Both technologies have the following problems when connecting the ultrafiltration membrane and the injection molded part: the ultrafiltration membrane material and the injection molded part cannot be welded together due to the difference in material or the difference in melting point of the two materials; the pore size of the ultrafiltration membrane ranges from 1nm to tens of nm, and the pore structure is destroyed during ultrasonic welding or hot melt welding, and the integrity effect cannot be achieved; whether it is ultrasonic welding or hot melt welding, there is a certain degree of damage to the injection molded part, the strength is reduced, and the later ultrafiltration centrifuge tube products are prone to rupture during high-speed centrifugation.

[0005] Therefore, how to achieve complete connection between the injection molded parts of the ultrafiltration centrifuge tube and the ultrafiltration membrane so as to ensure the protein recovery rate when the ultrafiltration centrifuge tube is used in a high-speed centrifuge requires a lot of experimental research to determine. Summary of the invention

[0006] In view of this, the object of the present invention is to provide an ultrafiltration centrifuge tube with high protein recovery rate and a method for connecting and fixing the ultrafiltration membrane thereof, so as to achieve complete connection between the injection molded part of the ultrafiltration centrifuge tube and the ultrafiltration membrane, and ensure the protein recovery rate when the ultrafiltration centrifuge tube is used in a high-speed centrifuge.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The invention discloses a method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifugal tube. The ultrafiltration centrifugal tube comprises an outer tube and an inner tube. A filtering part is arranged on the inner tube. The ultrafiltration membrane is bonded to the filtering part by glue point-gluing.

[0009] The parameters of the glue point bonding are:

[0010] The glue is acrylic structural glue and is cured by LED light source. The amount of glue dispensed is 0.0162-0.0168g.

[0011] The parameters of the dispensing test are: pressure 0.02kgf / cm 2 , glue dispensing speed 0.1 rev / s, sucking back speed 0.15 rev / s, moving speed 20mm / s, needle aperture 0.38mm, dispensing speed between 15%-30%.

[0012] As a preferred technical solution, the glue model is Henkel AA3211 glue, and its molecular formula is C 16 H 22 N 2 O 5 .

[0013] As a preferred technical solution, a glycerol solution with a mass fraction of 20% is used as a surface protective agent for the ultrafiltration membrane.

[0014] As a preferred technical solution, the ultrafiltration membrane is a polyethersulfone microporous membrane.

[0015] As a preferred technical solution, the molecular weight cut-off of the ultrafiltration membrane is 5-100KD.

[0016] The invention also discloses an ultrafiltration centrifugal tube prepared by adopting the ultrafiltration membrane connection and fixing method.

[0017] The beneficial effects of the present invention are:

[0018] The present invention bonds the ultrafiltration membrane to the filter part through a glue dispensing process, and studies and optimizes factors that can affect the bonding integrity of the ultrafiltration membrane, such as glue component selection, glue dispensing amount, glue dispensing uniformity, and curing method, so that the glue residue after glue dispensing bonding is extremely low and glue overflow is avoided, the glue dispensing surface is uniform and complete, and the bonding strength is high, so that the ultrafiltration centrifuge tube achieves a higher protein recovery rate when used in a high-speed centrifuge. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0020] Figure 1 This is a photo of the experimental results of the dispensing amount of 0.02g;

[0021] Figure 2 This is a photo of the experimental results of the dispensing amount of 0.016g;

[0022] Figure 3 This is a photo of the experimental results with a dispensing amount of 0.012g. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0024] Note: The ultrafiltration membrane in the following examples adopts a 10KD PES membrane produced by the applicant of the present invention.

[0025] Embodiment 1: Light curing and glue selection

[0026] Experimental process: Use automatic dispensing equipment.

[0027] 1. Experimental parameters:

[0028] The parameter is pressure: 0.02kgf / cm 2 ;

[0029] Needle aperture: 0.38mm;

[0030] Glue discharging speed: 0.1 rpm;

[0031] Suction speed: 0.15 rpm;

[0032] Moving speed: 20mm / s.

[0033] 2. Use LED lamp and mercury lamp UV curing, and fix with glue of different brands. The experimental results are as follows:

[0034]

[0035] Analysis of experimental results: After comprehensively considering the effects of different light curing and different glue bonding on bonding effect, dissolution and operation complexity, Henkel 3211 glue was used and LED light source curing was selected.

[0036] Embodiment 2: Selection of glue dosage

[0037] Experimental process: Use automatic dispensing equipment.

[0038] The parameter is pressure: 0.02kgf / cm 2 ;

[0039] Needle aperture: 0.38mm;

[0040] Glue discharging speed: 0.1 rpm;

[0041] Suction speed: 0.15 rpm;

[0042] Moving speed: 20mm / s.

[0043] The dispensing amount was about 0.02g, and the test results were as follows:

[0044]

[0045] The dispensing amount was about 0.016g, and the test results were as follows:

[0046]

[0047] The dispensing amount was about 0.012g, and the test results were as follows:

[0048]

[0049] Analysis of experimental results: The dispensing amount should be controlled within the range of 0.0162-0.0168g to ensure the dispensing effect.

[0050] Example 3: Selection of dispensing speed

[0051] The dispensing equipment and experimental parameters adopt the equipment and parameters in Example 2.

[0052]

[0053]

[0054] Analysis of experimental results: The dispensing speed should be controlled between 15%-30% to ensure the dispensing effect.

[0055] Example 4: Selection of ultrafiltration membrane surface protective agent

[0056] 1. Three membrane surface protective agents, glycerol, sodium bisulfite and propylene glycol, were selected for experimental verification. The experimental results are shown in the following table:

[0057]

[0058] Analysis of experimental results: From the above table, it can be seen that using glycerol as the surface protective agent of the membrane is the best choice.

[0059] 2. Determine the optimal percentage of glycerol as a surface protective agent. The experimental results are shown in the following table:

[0060]

[0061] Analysis of experimental results: From the above table, it can be seen that using 20%wt glycerol solution as the surface protective agent of the membrane is the best choice.

[0062] Example 5: Validation experiment of ultrafiltration centrifuge tube (protein recovery test)

[0063] Test sample information

[0064]

[0065] Experimental procedures

[0066] Solution preparation: Weigh a certain amount of protein sample using an electronic balance, add it to PBS solution to completely dissolve it, and prepare the protein solution for later use.

[0067] Test process: 4 ml of protein solution was loaded into an ultrafiltration centrifuge tube and concentrated by centrifugation at 6000 g in a fixed-angle rotor until about 0.1 ml of the inner tube volume remained (centrifugation time was about 10-30 min, which varied for different proteins and KD models).

[0068] The concentrated liquid in the ultrafiltration centrifuge tube was aspirated, and the volume was made up to 4 ml with PBS solution. The absorbance at 280 nm was measured, and the concentration of the protein solution was calculated using the standard curve.

[0069] The absorbance of the filtrate from the outer tube of the ultrafiltration centrifuge tube was directly measured at a wavelength of 280 nm using an ultraviolet spectrophotometer, and the protein concentration of the filtrate was calculated using a standard curve.

[0070] Concentration recovery rate % = 100*C c / C 0 , where C 0 is the concentration of the sample protein stock solution, C c This is the concentration of concentrated tubulin after fixed volume.

[0071] Retention rate % = 100-100*V f *C f / (V 0 *C 0 ), where C 0 is the concentration of the sample protein stock solution, V 0 is the volume of the sample protein stock solution, C f is the protein concentration of the filtrate from the outer tube, V f is the volume of the filtrate from the outer tube.

[0072] Loss rate % = 100-100*C c / C 0 -100*V f *C f / (V 0 *C 0 ).

[0073] Test results:

[0074]

[0075]

[0076]

[0077] Analysis of experimental results: In the above table, MS is an ultrafiltration centrifuge tube prepared by the applicant of the present invention according to the glue-dispensing bonding method in the invention content, and S and K are ultrafiltration centrifuge tubes commercially available from other manufacturers. It can be seen from the data in the table that the protein recovery rate of MS when used in a high-speed centrifuge is higher than that of S and K, which proves that the glue-dispensing bonding method of the present invention can improve the protein recovery rate.

[0078] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifuge tube, characterized in that: The ultrafiltration centrifuge tube comprises an outer tube and an inner tube, the inner tube is provided with a filter part, and the ultrafiltration membrane is glued to the filter part by glue point; The parameters of the glue point bonding are: The glue is acrylic structural glue and is cured by LED light source. The amount of glue dispensed is 0.0162-0.0168g. The parameters of the dispensing test are: pressure 0.02kgf / cm 2 , glue dispensing speed 0.1 rev / s, sucking back speed 0.15 rev / s, moving speed 20mm / s, needle aperture 0.38mm, dispensing speed between 15%-30%.

2. The method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The glue model is Henkel AA3211 glue, and its molecular formula is C 16 H 22 N2O5.

3. The method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The surface of the ultrafiltration membrane uses a glycerol solution with a mass fraction of 20% as a surface protective agent for the ultrafiltration membrane.

4. The method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The ultrafiltration membrane is a polyethersulfone microporous membrane.

5. The method for connecting and fixing an ultrafiltration membrane of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The molecular weight cut-off of the ultrafiltration membrane is 5-100KD.

6. An ultrafiltration centrifuge tube prepared by the ultrafiltration membrane connection and fixing method according to any one of claims 1 to 5.

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