Ultrafiltration centrifuge tube and manufacturing method thereof

Abstract

The invention relates to an ultrafiltration centrifuge tube and a manufacturing method thereof.The ultrafiltration centrifuge tube comprises an inner tube, the inner tube comprises a center tube and a filter piece, the lower end of the center tube is oppositely provided with a first filter face and a filter hollowed-out part, the first filter face and the center tube are integrally formed, and a first membrane is fixed to the inner side of the first filter face through welding; a first membrane is fixed on the inner side of the filter sheet through welding, a second membrane is fixed on the inner side of the filter sheet through welding, the filter sheet is embedded and fixed in the filter hollow-out through welding to form a second filter surface, the first filter surface and the second filter surface are in mirror symmetry, the first filter surface and the second filter surface are both provided with filter holes, the inner pipe is sleeved with an outer pipe, and end openings of the inner pipe and the outer pipe are covered with pipe covers. A liquid storage cavity is formed in the inner pipe, a gap cavity is formed between the outer wall of the center pipe and the inner wall of the outer pipe, the liquid storage cavity and the gap cavity are communicated through the filtering holes, and the first membrane and the second membrane cover the filtering holes.

Description

Technical Field

[0001] The invention relates to the technical field of ultrafiltration centrifuge tubes, and in particular to an ultrafiltration centrifuge tube and a manufacturing method thereof. Background Art

[0002] Purification of macromolecular components from tissue culture medium extracts, purification of macromolecular components from cell lysates, removal of primers, linkers or molecular tags from reaction mixtures, and removal of proteins before HPLC; alternatively, desalting, buffer exchange or diafiltration all require the use of separation methods.

[0003] Membrane separation is an extremely efficient separation method. In the field of life sciences, membrane separation has gradually replaced traditional separation methods such as chemical precipitation, dialysis, and freeze-drying. However, membrane separation has very strict requirements when forming components. Poor sealing of local joints of components will cause leakage, seriously affecting the separation effect and making the experimental data unreliable. Among them, ultrafiltration is a membrane separation method that uses an ultrafiltration membrane with a certain retention capacity as the filtration medium and pressure difference as the driving force to separate extremely small particles and soluble molecules in the solution. Compared with traditional methods, ultrafiltration has the advantages of being gentle, convenient, fast and efficient, and isovolumetric ultrafiltration is very effective for sample desalination and buffer replacement.

[0004] An ultrafiltration centrifuge tube is generally composed of an outer tube, a base tube, a base sleeve, an ultrafiltration membrane and other components. The base tube, base sleeve and ultrafiltration membrane are assembled in the outer tube. The ultrafiltration membrane is set close to the filter holes on the surface of the base tube, and the base sleeve cooperates with the base tube to fix the ultrafiltration membrane. When in use, the ultrafiltration centrifuge tube containing the filtered stock solution is placed in a centrifuge for centrifugation. After the centrifuge is started, the filtered stock solution is continuously replenished in the base tube. In this way, the filtered stock solution is filtered and separated by the ultrafiltration membrane under the action of the centrifuge and then thrown into the bottom cavity of the outer tube, thereby realizing membrane separation.

[0005] 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.

[0006] However, the existing ultrafiltration centrifuge tubes still have a series of problems.

[0007] Existing ultrafiltration centrifuge tubes mostly use silicone sealing rings or adhesives to achieve sealing with plastic parts. The use of silicone rings for sealing is prone to leakage after being subjected to centrifugal force during use; the use of adhesives for sealing is prone to adhesive component residue, which increases the amount of dissolved matter and affects the final test results; and the adhesive has a long curing time, which reduces the efficiency of sealing and assembly; these existing methods have a poor user experience and also affect the separation effect and the impurity content of the finished product. Summary of the invention

[0008] Based on this, it is necessary to provide an ultrafiltration centrifuge tube and a method for manufacturing the same.

[0009] On the one hand, an embodiment of the present invention provides an ultrafiltration centrifuge tube, including an inner tube, the inner tube including a central tube and a filter plate, the lower end of the central tube is relatively provided with a first filter surface and a filter hollow, the first filter surface and the central tube are integrally formed, a first diaphragm is fixed to the inner side of the first filter surface by welding, a second diaphragm is fixed to the inner side of the filter plate by welding, the filter plate is fixed in the filter hollow by welding and inlaying to form the second filter surface, the first filter surface and the second filter surface are mirror-symmetrical, the first filter surface and the second filter surface both have filter holes, an outer tube is arranged outside the inner tube, the port covers of the inner tube and the outer tube are provided with a tube cover, a liquid storage cavity is provided in the inner tube, a gap cavity is formed between the outer wall of the central tube and the inner wall of the outer tube, the filter hole connects the liquid storage cavity and the gap cavity, and the first diaphragm and the second diaphragm cover the filter hole.

[0010] Preferably, the first membrane and the second membrane are both ultrafiltration membranes, and the ultrafiltration membrane is a flat ultrafiltration membrane.

[0011] Preferably, an annular diaphragm welding area is provided on the inner side of the central tube at the periphery of the first filter surface, the first diaphragm covers the first filter surface of the central tube, the periphery of the first diaphragm covers the diaphragm welding area, and the first diaphragm is fixed by welding.

[0012] Preferably, an annular filter plate welding area is provided on the outer side of the central tube at the peripheral edge of the filter hollow, and the membrane filter plate is embedded in the filter hollow so that the peripheral edge of the membrane filter plate covers the filter plate welding area, and the membrane filter plate is fixed by welding.

[0013] Preferably, a step surface is formed on the circumference of the filter plate, the step surface abuts against the welding area of ​​the filter plate, and the step surface and the welding area of ​​the filter plate are fixed by welding.

[0014] Preferably, the welding method includes one of hot melt welding, high frequency welding, ultrasonic welding and laser welding.

[0015] Preferably, the inner tube is concentrically arranged with the outer tube, the outer edge of the inner tube's pipe opening is overlapped with the inner edge of the outer tube's pipe opening, a positioning groove is arranged at the inner edge of the outer tube's pipe opening, and a positioning block is correspondingly arranged at the outer edge of the inner tube's pipe opening, and the positioning block is aligned and overlapped in the positioning groove.

[0016] Preferably, an anti-rolling boss is provided on the outer surface of the tube cover, and the anti-rolling boss is higher than the outer surface of the tube cover and forms an anti-rolling plane.

[0017] Preferably, the anti-roll plane is perpendicular to a line connecting the centers of the tube covers.

[0018] On the other hand, a method for manufacturing an ultrafiltration centrifuge tube is also provided, comprising the following steps:

[0019] S1, manufacturing an integrally formed central tube;

[0020] S2, manufacturing the filter sheet so that the shape and size of the filter sheet match the filter hollowing, covering the inner side of the filter sheet with the second membrane sheet and fixing it by welding to obtain a membrane-coated filter sheet;

[0021] S3, covering the first diaphragm on the first filter surface of the central tube so that the circumference of the first diaphragm covers the diaphragm welding area, and fixing the first diaphragm by welding;

[0022] S4, inlaying the membrane-coated filter sheet in step S2 into the filter hollow portion, so that the periphery of the membrane-coated filter sheet covers the filter sheet welding area, and fixing the membrane-coated filter sheet by welding to obtain an inner tube of an ultrafiltration centrifuge tube;

[0023] S5. Perform an air tightness test on the inner tube manufactured in step S4. If the air tightness is qualified, assemble it with the outer tube and the tube cover to obtain an ultrafiltration centrifuge tube.

[0024] The ultrafiltration centrifuge tube and the stable and reliable separation membrane and the efficient method for sealing and fixing the plastic part provided by the present invention avoid leakage problems during high-speed centrifugation of the ultrafiltration centrifuge tube, shorten the welding process, and improve the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other purposes, features and advantages of the present invention will become more clear by more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the accompanying drawings are not deliberately scaled to the actual size, and the focus is on illustrating the main purpose of the present invention.

[0026] Figure 1 A three-dimensional diagram of an inner tube of a preferred embodiment of the present invention;

[0027] Figure 2 A side view of an inner tube according to a preferred embodiment of the present invention;

[0028] Figure 3 for Figure 2 Sectional view at AA` in the middle;

[0029] Figure 4 is a three-dimensional diagram of a central tube according to an embodiment of the present invention;

[0030] Figure 5 This is a schematic structural diagram of an outer tube according to an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of the structure of a tube cover according to an embodiment of the present invention;

[0032] Figure 7 A schematic structural diagram of a tube cover from another perspective of an embodiment of the present invention;

[0033] Outer tube 1; inner tube 2; center tube 3; filter plate 4; first filter surface 5; first membrane 7; membrane welding area 10; filter hollow 9; second filter surface 6; filter plate welding area 11; tube cover 20; anti-roll boss 14; anti-roll plane 15; positioning block 17; positioning groove 18; liquid storage chamber 19; air pressure balance port 21. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described in detail 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.

[0035] like Figure 1-Figure 7As shown, an ultrafiltration centrifuge tube comprises an inner tube 2, the inner tube 2 comprises a central tube 3 and a filter sheet 4, a first filter surface 5 and a filter hollow 9 are arranged opposite to each other at the lower end of the central tube 3, the first filter surface 5 is integrally formed with the central tube 3, a first diaphragm 7 is fixed to the inner side of the first filter surface 5 by welding, a second diaphragm is fixed to the inner side of the filter sheet 4 by welding, the filter sheet 4 is inlaid and fixed in the filter hollow 9 by welding to form a second filter surface 6, the first filter surface 5 and the second filter surface 6 are mirror-symmetrical, the first filter surface 5 and the second filter surface 6 both have filter holes, an outer tube 1 is arranged on the outer sleeve of the inner tube 2, a tube cover 20 is arranged on the port covers of the inner tube 2 and the outer tube 1, a liquid storage cavity 19 is arranged in the inner tube 2, a gap cavity is formed between the outer wall of the central tube 3 and the inner wall of the outer tube 1, the filter hole connects the liquid storage cavity 19 and the gap cavity, the first diaphragm 7 and the second diaphragm cover the filter holes on the first filter surface 5 and the second filter surface 6 respectively. Compared with the existing ultrafiltration tube that uses adhesives and sealing rings to seal the ultrafiltration membrane, the present invention uses integrated molding and welding to fix the ultrafiltration membrane, so that the structural strength of the fixed structure of the first filter surface 5 and the second filter surface 6 is higher, and it can withstand higher centrifugal speeds, the filtration speed is faster, and the risk of leakage is smaller. Moreover, since the use of adhesives to fix the ultrafiltration tube is avoided, the filtrate dissolution is extremely low and the biosafety is better. Among them, the first diaphragm 7 and the second diaphragm are both cut from ultrafiltration membranes.

[0036] In a preferred embodiment, the first diaphragm 7 and the second diaphragm are both flat ultrafiltration membranes; preferably, the flat ultrafiltration membrane is a PES ultrafiltration membrane with a non-woven fabric support; optionally, the center tube 3 and the filter plate 4 are both made of plastic. Preferably, the center tube and the filter plate that form the same inner tube are made of the same material. The center tube and the filter plate are made of any one of polystyrene (PS for short), polypropylene (PP for short), polystyrene butadiene copolymer (SBR for short), and polystyrene-butadiene-acrylonitrile copolymer (ABS for short); or, the center tube and the filter plate are made of a blend of any two or more of the above materials.

[0037] In a preferred embodiment, an annular diaphragm welding area 10 is provided on the inner side of the central tube 3 at the periphery of the first filter surface 5, the first diaphragm 7 covers the first filter surface 5 of the central tube 3, the periphery of the first diaphragm 7 covers the diaphragm welding area 10, and the first diaphragm 7 is fixed to the inner side of the first filter surface 5 of the central tube 3 by welding.

[0038] In a preferred embodiment, an annular filter plate welding area 11 is provided on the outer side of the central tube 3 at the periphery of the filter hollow 9, and the membrane-coated filter plate 4 is embedded in the filter hollow 9 so that the periphery of the membrane-coated filter plate 4 covers the filter plate welding area 11, and the membrane-coated filter plate 4 is fixed by welding. The inner tube 2 of the present invention makes the first filter surface 5 and the central tube 3 integrally formed, and at the same time, the filter plate 4 on the opposite side is fixed to the central tube by embedding and welding, thereby ensuring the sealing performance; the ultrafiltration centrifuge tube provided by the present invention, on the one hand, ensures the sealing performance between the membrane and the filter plate, and between the filter plate and the centrifuge tube, avoids the problem of leakage of the ultrafiltration centrifuge tube during high-speed centrifugation, and ensures the retention rate of the feed liquid. In addition, the process of sealing and assembling parts is reduced through structural improvement, thereby improving efficiency, and making the product qualification rate higher.

[0039] In a preferred embodiment, a step surface is formed on the circumference of the filter plate 4 , the step surface abuts against the filter plate welding area 11 , and the step surface and the filter plate welding area 11 are fixed by welding.

[0040] In a preferred embodiment, the welding method includes one of hot melt welding, high frequency welding, ultrasonic welding, and laser welding.

[0041] In a preferred embodiment, the inner tube 2 is concentrically arranged with the outer tube 1, the outer edge of the tube mouth of the inner tube 2 is arranged on the inner edge of the tube mouth of the outer tube 1, a positioning groove 18 is arranged on the inner edge of the tube mouth of the outer tube 1, and a positioning block 17 is arranged on the outer edge of the tube mouth of the inner tube 2, and the positioning block 17 is arranged in the positioning groove 18.

[0042] In a preferred embodiment, the outer surface of the tube cover 20 is provided with an anti-rolling boss 14, which is higher than the outer surface of the tube cover 20 and forms an anti-rolling plane 15. The tube cover 20 has the anti-rolling boss 14, and the tube cover 20 is screwed with the inner tube and the outer tube by threads. The anti-rolling boss 14 can prevent the ultrafiltration centrifuge tube from rolling when placed on the desktop. At the same time, there is an inclination angle between the axis of the ultrafiltration centrifuge tube and the desktop, making it more convenient to store, preventing the liquid from flowing out due to flat placement, and preventing the membrane surface from drying out and causing the pores to shrink or crack.

[0043] In a preferred embodiment, the anti-roll plane 15 is perpendicular to a line connecting the centers of the tube cover 20 .

[0044] The method for manufacturing an ultrafiltration centrifuge tube is characterized in that it comprises the following steps:

[0045] S1, a central tube 3 manufactured by integral molding;

[0046] S2, manufacturing a filter sheet 4 so that the shape and size of the filter sheet 4 match the shape of the filter hollow 9, covering the inner side of the filter sheet 4 with a second membrane and fixing it by welding to obtain a membrane-coated filter sheet 4;

[0047] S3, covering the first diaphragm 7 on the first filter surface 5 of the central tube 3, so that the circumference of the first diaphragm 7 covers the diaphragm welding area 10, and fixing the first diaphragm 7 by welding;

[0048] S4, inlaying the membrane-coated filter sheet 4 in step S2 into the filter hollow 9, so that the periphery of the membrane-coated filter sheet 4 covers the filter sheet welding area 11, and fixing the membrane-coated filter sheet 4 by welding, thereby manufacturing the inner tube 2 of the ultrafiltration centrifuge tube;

[0049] S5, the inner tube 2 manufactured in step S4 is subjected to an air tightness test, and if the air tightness is qualified, it is assembled with the outer tube and the tube cover to obtain an ultrafiltration centrifuge tube. The first filter surface 5 is integrally formed with the central tube 3, and this integrally formed structure does not require secondary welding, which reduces one welding process. Compared with the ultrafiltration tube with a welded structure on the market, only one filter plate needs to be welded, that is, the filter plate 4 is embedded in the filter hollow 9, and the coated filter plate 4 is fixed by welding, which simplifies the process, improves production efficiency, and improves the product qualification rate.

[0050] It should be noted that when the airtightness test is performed by detecting the airtightness leakage of the inner tube 2, if the airtightness leakage is lower than the set value, it is determined that the airtightness is qualified.

[0051] It should be noted that the inner tube 2 includes a cylinder for storing liquid at the upper end and a bottom end for filtering the internal liquid at the lower end. The port caps of the inner tube 2 and the outer tube 1 are provided with a tube cover 20, through which the inner tube 2 and the outer tube 1 can be sealed at the same time. The tube cover 20 is used to prevent the liquid in the liquid storage chamber 19 and the gap chamber from being thrown out of the centrifuge tube assembly during the centrifugation process. During the centrifugation process, the liquid in the liquid storage chamber 19 filtered by the membrane gradually passes through the filter holes to reach the gap chamber, thereby realizing protein concentration and desalting, buffer replacement, collection of proteins or other molecules in cell supernatants or lysates, and removal of macromolecular particles.

[0052] In order to better illustrate the technical solution of the present invention, several embodiments are now cited to further illustrate the effects thereof.

[0053] Example 1

[0054] According to the above structure and manufacturing method of the present application, corresponding plastic parts are produced, and the plastic parts include a central tube and a filter plate.

[0055] The 30kD PES ultrafiltration membrane with non-woven fabric support is cut into membrane sheets, and the membrane sheets are welded to the membrane welding area of ​​the central tube by heat welding. At the same time, the ultrafiltration membrane is welded to the membrane welding area of ​​the filter sheet, and then the filter sheet is welded to the filter sheet welding area of ​​the central tube by ultrasonic welding. The inner tube of the ultrafiltration tube is completed.

[0056] (1) Inner tube air tightness test

[0057] The inner tube is tested for air tightness on an air tightness tester to detect gas leakage. The air tightness is qualified when the air tightness leakage is ≤0.3mL / min.

[0058] The parameters for air tightness testing are: inflation time is set to 10s, pressure holding time is 15s, and pressure holding pressure is 200kpa.

[0059] 50 inner tube samples were taken for air tightness testing, and the air tightness test data were shown in Table 1 below:

[0060] Table 1

[0061]

[0062] From the results of the air tightness test in Table 1, the air tightness leakage of 50 inner tube samples was less than 0.3 mL / min. It can be seen that the inner tubes produced using the centrifuge tube structure and manufacturing method of the present invention have excellent air tightness and a high product qualification rate.

[0063] (2) Testing the BSA retention rate of the ultrafiltration tube

[0064] 24 inner tubes were extracted from the 50 inner tube samples that had undergone air tightness testing and had air tightness leakage of less than 0.3 mL / min, and assembled into 24 ultrafiltration tubes with the outer tubes and tube covers prepared according to the method and structure of the present application.

[0065] The BSA retention rate of these 24 ultrafiltration tubes was tested using a centrifuge:

[0066] The protein solution was 1000mg / L BSA solution; 24 ultrafiltration tubes were randomly divided into three groups, 8 in each group; the centrifugal force of the centrifuge was set to 2000×g, 3000×g, and 4000×g, and the centrifugation time of the three groups was the same. The average value of the 8 data in each group was obtained to obtain the test results shown in Table 2 below:

[0067] Table 2

[0068] Centrifugal force 2000×g 3000×g 4000×g Average interception rate / % 98.6 98.4 98.3 Average recovery rate / % 93.2 92.8 92.4

[0069] The interception rate data described in Table 2 above indicate that the sealing of the inner tube package is good, and under high-speed centrifugation, there is no rupture or leakage at the welding positions of the membrane and the filter.

[0070] Example 2

[0071] According to the above structure and manufacturing method of the present application, corresponding plastic parts are produced, and the plastic parts include a central tube and a filter plate.

[0072] The 10kD PES ultrafiltration membrane with non-woven fabric support is cut into membrane sheets, and the membrane sheets are welded to the membrane welding area of ​​the central tube by heat welding. At the same time, the ultrafiltration membrane is welded to the membrane welding area of ​​the filter sheet, and then the filter sheet is welded to the filter sheet welding area of ​​the central tube by ultrasonic welding. The inner tube of the ultrafiltration tube is completed.

[0073] (1) Inner tube air tightness test

[0074] Perform an air tightness test on the manufactured inner tube on an air tightness tester to detect gas leakage;

[0075] The parameters for air tightness testing are: inflation time is set to 10s, pressure holding time is 15s, and pressure holding pressure is 200kpa.

[0076] 100 inner tube samples were taken for air tightness testing, and the air tightness test data were shown in Table 3 below:

[0077] Table 3

[0078]

[0079] Taking the airtightness leakage of ≤0.3mL / min as the criterion for airtightness qualification, it can be seen from the results in Table 3 that the qualified rate of 100 inner tube samples is 99%.

[0080] (2) Testing the cytochrome C retention rate of the ultrafiltration tube

[0081] 13 qualified inner tubes were extracted from the 100 inner tube samples that had undergone air tightness testing and had an air tightness leakage of less than 0.3 mL / min, and assembled with the outer tubes and tube covers prepared according to the method and structure of the present application to form 13 qualified ultrafiltration tubes; this was a qualified ultrafiltration tube group.

[0082] At the same time, a substandard inner tube with an airtight leakage greater than 0.3 mL / min is taken and assembled with the outer tube and tube cover prepared according to the method and structure of the present application to form a substandard ultrafiltration tube, which is a substandard ultrafiltration tube set.

[0083] The solutions were all 1000 mg / L cytochrome C solution; the centrifugal force of the centrifuge was set at 2000×g; the centrifugation time of the qualified ultrafiltration tube group and the unqualified ultrafiltration tube group was the same. The ultrafiltration tube test cytochrome C retention data test results shown in Table 4 below were obtained:

[0084] Table 4

[0085] Ultrafiltration tube type Qualified ultrafiltration tube Unqualified ultrafiltration tube Average interception rate / % 96.8 86.3 Average recovery rate / % 91.3 79.2

[0086] From the retention rate data in Table 4, we can see that the retention rate and recovery rate of qualified ultrafiltration tubes are very high, both > 90%, and can well retain cytochrome C. The retention rate of cytochrome C of unqualified ultrafiltration tubes is low.

[0087] Example 3

[0088] According to the above structure and manufacturing method, corresponding plastic parts are produced, and the plastic parts include a central tube and a filter sheet.

[0089] The 3kD PES ultrafiltration membrane with non-woven fabric support is welded to the central tube membrane welding area by heat welding, and the ultrafiltration membrane is welded to the membrane welding area of ​​the filter sheet at the same time, and then the filter sheet is welded to the central tube filter sheet welding area by ultrasonic welding. The inner tube of the ultrafiltration tube is completed.

[0090] (1) Inner tube air tightness test

[0091] The inner tube is tested for air tightness on an air tightness tester to detect gas leakage. The air tightness is qualified when the air tightness leakage is ≤0.3mL / min.

[0092] The parameters for air tightness testing are: inflation time is set to 10s, pressure holding time is 15s, pressure holding pressure is 200kpa, and gas leakage is detected.

[0093] The above 30 inner tube samples were taken for air tightness testing, and the air tightness test data were shown in Table 5 below:

[0094] Table 5

[0095]

[0096] From the results of the airtightness test in Table 1, the qualified rate of the inner tube samples in this test is 100%.

[0097] (2) Testing the cytochrome C retention rate of the ultrafiltration tube

[0098] 14 inner tubes were selected from the 30 inner tube samples that had been tested for air tightness and passed the air tightness test, and assembled into 14 ultrafiltration tubes to test cytochrome C retention:

[0099] The solutions were all 1000 mg / L cytochrome C solutions; 14 ultrafiltration tubes were randomly divided into two groups, 7 in each group; the centrifugation time of the two groups was the same, and the retention data were as shown in Table 6:

[0100] Table 6

[0101] Centrifugal force Fixed angle centrifugation 4000×g Swinging bucket centrifuge 5000×g Average interception rate / % 96.8 96.6 Average recovery rate / % 91.3 91.2

[0102] From the data in Table 6, it can be seen that the retention rate and recovery rate of the qualified ultrafiltration tube are very high, both of which are greater than 90%, and can well retain cytochrome C.

[0103] Example 4

[0104] According to the above structure and manufacturing method of the present application, corresponding plastic parts are produced, and the plastic parts include a central tube and a filter plate.

[0105] The 50kD PES ultrafiltration membrane with non-woven fabric support is cut into membrane sheets, and the membrane sheets are welded to the membrane welding area of ​​the central tube by heat welding. At the same time, the ultrafiltration membrane is welded to the membrane welding area of ​​the filter sheet, and then the filter sheet is welded to the filter sheet welding area of ​​the central tube by ultrasonic welding. The inner tube of the ultrafiltration tube is completed.

[0106] (1) Inner tube air tightness test

[0107] The inner tube is tested for air tightness on an air tightness tester to detect gas leakage. The air tightness is qualified when the air tightness leakage is ≤0.3mL / min.

[0108] The parameters for air tightness testing are: inflation time is set to 10s, pressure holding time is 15s, and pressure holding pressure is 200kpa.

[0109] 100 inner tube samples were taken for air tightness testing, and the air tightness test data were shown in Table 7 below:

[0110] Table 7

[0111]

[0112] According to the results of the airtightness test in Table 7, the pass rate of the samples produced this time is 98%.

[0113] (2) Testing the BSA retention rate of the ultrafiltration tube

[0114] 14 inner tubes were extracted from the above samples with qualified air tightness to make 14 ultrafiltration tubes to test 1000 mg / L BSA retention. The retention data are shown in Table 8 below:

[0115] Table 8

[0116] Centrifugal force Fixed angle centrifugation 4000×g Swinging bucket centrifuge 5000×g Average interception rate / % 94.3 94.6 Average recovery rate / % 90.6 90.8

[0117] From the data table 8, it can be seen that the ultrafiltration tube with qualified air tightness has a very high retention rate and recovery rate, both above 90%, and can well retain BSA.

[0118] Example 5

[0119] According to the above structure and manufacturing method of the present application, corresponding plastic parts are produced, and the plastic parts include a central tube and a filter plate.

[0120] The 100kD PES ultrafiltration membrane with non-woven fabric support is cut into membrane sheets, and the membrane sheets are welded to the membrane welding area of ​​the central tube by heat welding. At the same time, the ultrafiltration membrane is welded to the membrane welding area of ​​the filter sheet, and then the filter sheet is welded to the filter sheet welding area of ​​the central tube by ultrasonic welding. The inner tube of the ultrafiltration tube is completed.

[0121] (1) Inner tube air tightness test

[0122] The inner tube manufactured above is tested for air tightness on an air tightness tester to detect gas leakage, and the air tightness is qualified when the air tightness leakage is ≤0.3mL / min;

[0123] The parameters for air tightness testing are: inflation time is set to 10s, pressure holding time is 15s, and pressure holding pressure is 200kpa.

[0124] A total of 200 inner tube samples were taken for air tightness test, and the air tightness test data shown in Table 9 below were obtained:

[0125] Table 9

[0126]

[0127] We internally set the leakage rate of 50kD ultrafiltration tubes to be ≤0.3mL / min as qualified, and the qualified rate of the samples produced this time was 97%.

[0128] (2) Testing the IGG retention rate of the ultrafiltration tube

[0129] 14 inner tubes were extracted from the 200 inner tube samples that were tested for air tightness and qualified for air tightness and assembled into ultrafiltration tubes. The retention of 1000 mg / L IGG solution was tested, and the retention data were shown in Table 10 below:

[0130] Table 10

[0131] Centrifugal force Fixed angle centrifugation 4000×g Swinging bucket centrifuge 5000×g Average interception rate / % 98.6 97.8 Average recovery rate / % 93.6 92.7

[0132] (3) Ultrafiltration tube reuse test

[0133] The 14 ultrafiltration tubes tested for IGG retention rate in (2) above were used for repeated use test to test IGG retention rate. After each filtration, they were soaked in 1 mol / L sodium hydroxide solution for 10 minutes, then washed with pure water and used to filter protein solution. This was repeated for 20 cycles to detect changes in retention rate and air tightness of each ultrafiltration tube. The data shown in Table 11 below were obtained:

[0134] Table 11

[0135] 1st centrifugation 20th Centrifugation Airtightness ＜0.3 ＜0.3 Average interception rate / % 98.6 98.8

[0136] It can be seen from Table 11 that after 20 centrifugations, the retention rate did not change significantly, and the air tightness did not change either, which indicates that the inner tube connection strength obtained by the centrifuge tube structure and method of the present invention is high.

[0137] In summary, from the data of Examples 1-5, the retention rate and recovery rate of the qualified ultrafiltration tube are very high, both > 90%, and the target protein (ie, IGG) can be well retained.

[0138] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An ultrafiltration centrifuge tube, characterized in that: The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface. The filter element is a filter element having a first filter surface and a second filter surface.

2. The ultrafiltration centrifuge tube according to claim 1, characterized in that The first membrane and the second membrane are both ultrafiltration membranes, and the ultrafiltration membrane is a flat ultrafiltration membrane.

3. The ultrafiltration centrifuge tube according to claim 1, characterized in that An annular diaphragm welding area is provided on the inner side of the central tube at the periphery of the first filter surface. The first diaphragm covers the first filter surface of the central tube. The periphery of the first diaphragm covers the diaphragm welding area, and the first diaphragm is fixed by welding.

4. The ultrafiltration centrifuge tube according to claim 3, characterized in that: An annular filter plate welding area is provided on the outer side of the central tube at the peripheral edge of the filter hollow, and the membrane filter plate is embedded in the filter hollow so that the peripheral edge of the membrane filter plate covers the filter plate welding area, and the membrane filter plate is fixed by welding.

5. The ultrafiltration centrifuge tube according to claim 1, characterized in that A step surface is formed on the circumference of the filter plate, the step surface abuts against the welding area of ​​the filter plate, and the step surface and the welding area of ​​the filter plate are fixed by welding.

6. The ultrafiltration centrifuge tube according to claim 1, characterized in that The welding method includes one of hot melt welding, high frequency welding, ultrasonic welding and laser welding.

7. The ultrafiltration centrifuge tube according to claim 1, characterized in that: The inner tube is concentrically arranged with the outer tube, the outer edge of the inner tube's pipe opening is placed on the inner edge of the outer tube's pipe opening, a positioning groove is arranged on the inner edge of the outer tube's pipe opening, and a positioning block is correspondingly arranged on the outer edge of the inner tube's pipe opening, and the positioning block is aligned and placed in the positioning groove.

8. The ultrafiltration centrifuge tube according to claim 1, characterized in that: The outer surface of the tube cover is provided with an anti-rolling boss, and the anti-rolling boss is higher than the outer surface of the tube cover and forms an anti-rolling plane.

9. The ultrafiltration centrifuge tube according to claim 8, characterized in that: The anti-roll plane is perpendicular to a line connecting the centers of the tube covers.

10. The method for manufacturing an ultrafiltration centrifuge tube according to claims 1 to 9, characterized in that: The steps include: S1, manufacturing an integrally formed central tube; S2, manufacturing the filter sheet so that the shape and size of the filter sheet match the filter hollowing, covering the inner side of the filter sheet with the second membrane sheet and fixing it by welding to obtain a membrane-coated filter sheet; S3, covering the first diaphragm on the first filter surface of the central tube so that the circumference of the first diaphragm covers the diaphragm welding area, and fixing the first diaphragm by welding; S4, inlaying the membrane-coated filter sheet in step S2 into the filter hollow portion, so that the periphery of the membrane-coated filter sheet covers the filter sheet welding area, and fixing the membrane-coated filter sheet by welding to obtain an inner tube of an ultrafiltration centrifuge tube; S5. Perform an air tightness test on the inner tube manufactured in step S4. If the air tightness is qualified, assemble it with the outer tube and the tube cover to obtain an ultrafiltration centrifuge tube.

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