A method for detecting ultrafiltration effect of ultrafiltration centrifuge tube

Abstract

The invention discloses a detection method for an ultrafiltration tube, aiming to provide an ultrafiltration effect detection method for an ultrafiltration centrifuge tube with good detection effect, high detection accuracy and the ability to intuitively compare multiple groups of products that do not pass through the ultrafiltration tube. The key points of the technical scheme are to build a complete ultrafiltration tube performance evaluation system by integrating pretreatment, membrane integrity inspection, dynamic flow rate analysis and protein recovery rate determination, and to judge the flow rate curve and protein recovery rate of the ultrafiltration tube based on multiple periods of centrifugation and finished product OD values. The overall experimental data is reliable and has a small deviation. Multiple groups of different ultrafiltration tubes can be inspected, and data comparison is performed at the same time to obtain the ultrafiltration tube that is most suitable for the current experiment. The test scheme of the application can well evaluate the ultrafiltration effect of the ultrafiltration tube. The invention is suitable for the field of ultrafiltration tube detection.

Description

Technical Field

[0001] The present invention relates to a method for detecting an ultrafiltration tube, and more specifically, to a method for detecting the ultrafiltration effect of an ultrafiltration centrifugal tube. Background Art

[0002] As an efficient experimental tool combining ultrafiltration technology and centrifugal separation, ultrafiltration centrifuge tubes are widely used in the fields of biomedicine, environmental monitoring and chemical analysis. Its core function is to achieve the concentration, desalting and buffer exchange of biomacromolecules (such as proteins and nucleic acids) through ultrafiltration membranes with specific molecular weight cutoff (MWCO). However, the detection method of ultrafiltration effect in the prior art still has the following limitations: 1. The existing ultrafiltration tubes need to be rinsed before use to remove the protective agent (such as glycerol and sodium azide), but the cleaning steps lack unified specifications, and the residues may interfere with the test results, making the standardization of the early pretreatment of the ultrafiltration tube insufficient; 2. The existing technology mostly relies on visual inspection or simple pressure testing, and it is impossible to quantitatively evaluate the uniformity of the microporous structure, resulting in the loss of ultrafiltration membrane integrity, thereby affecting the overall recovery rate. At the same time, different ultrafiltration tubes have different protein recovery rates and protein concentration flow rates. In order to maximize the benefits and improve the efficiency of production, it is necessary to detect multiple groups of ultrafiltration tubes at the same time to obtain the best product. Therefore, a method for detecting the ultrafiltration effect of ultrafiltration tubes is urgently needed. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for detecting the ultrafiltration effect of an ultrafiltration centrifuge tube, which has good detection effect, high detection accuracy and can intuitively compare multiple groups of samples that do not pass through the ultrafiltration tube.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube, comprising the following steps: S11, cleaning the ultrafiltration tube: adding a buffer solution into the ultrafiltration tube so that the buffer solution covers the ultrafiltration membrane in the ultrafiltration tube, and placing the ultrafiltration tube in an environment of 4°C for a period of time T;

[0005] S12, residual liquid removal: after the T time period, the ultrafiltration tube is subjected to inverted centrifugation to remove the residual buffer in the ultrafiltration tube;

[0006] S13, component weighing: weigh the components of the ultrafiltration tube after cleaning and removing residual liquid, and measure the weight of the centrifuge tube as Wg and the weight of the filter as Wq;

[0007] S14, adding sample: adding an experimental sample into the treated ultrafiltration tube, wherein the experimental sample is cytochrome C, and the added amount thereof is V;

[0008] S15, centrifugation: centrifuging the ultrafiltration tube containing cytochrome C, and setting the centrifugation time to T1, T2, T3, and T4 respectively;

[0009] S16, finished product measurement: after centrifugation is completed, the weights of the centrifuge tubes are measured, which are W1, W2, W3, and W4;

[0010] S17, volume measurement: according to the weight of the centrifuge tube, the volume of the liquid filtered out at each centrifugation time is calculated to be V1, V2, V3, and V4 respectively;

[0011] S18. Draw a flow rate curve of each ultrafiltration tube based on the measured liquid volume.

[0012] The present invention is further configured as follows: the detection method further includes the determination of protein recovery rate, comprising the following steps: S21, calculating the protein recovery rate curve: performing multiple measurements at different gradients of cytochrome C concentrations, taking the OD value at 450nm as a reference, making a standard curve, and obtaining the relationship between the OD value and the cytochrome C concentration according to the standard curve;

[0013] S22. Prepare sample solution: weigh in advance and prepare 0.25 mg / ml cytochrome C, the concentration is recorded as Ca, and the average value is obtained after three cycles;

[0014] S23, cleaning pretreatment of the ultrafiltration tube: cleaning the ultrafiltration tube and removing residual liquid;

[0015] S24, adding cytochrome C into the pre-treated ultrafiltration tube, and recording the volume of cytochrome C as Va;

[0016] S25, centrifugation: centrifuge the ultrafiltration tube containing the sample for a centrifugal time of Ta. After the Ta period, record the volume of the concentrated protein in the ultrafiltration tube as Vb. Simultaneously measure the OD value of the concentrated protein, and calculate the current concentration Cb of the concentrated protein according to the standard curve in step S21. Measure three times and take an average value.

[0017] S26. Recovery rate calculation: Calculate the recovery rate of the concentrated protein in the current ultrafiltration tube based on Va, Ca, Vb, and Cb.

[0018] Preferably, the step S11 further includes an integrity test of the ultrafiltration membrane, including the following steps: S111, injecting pure water into the ultrafiltration tube until the ultrafiltration tube is completely wetted;

[0019] S112, applying 0.3 MPa gas pressure and observing the ultrafiltration tube for a period of time T;

[0020] S113. Within the T time period, if the ultrafiltration tube does not generate continuous bubbles, the current ultrafiltration membrane is judged to be qualified; otherwise, the current ultrafiltration membrane is judged to be unqualified.

[0021] Preferably, the method of removing residual liquid by inverted centrifugation in step S12 comprises the following steps: S121, inverting the filter inside the ultrafiltration tube into a new collection tube, and centrifuging at 1000g for a period of time T;

[0022] S122. After the T time period, detect whether there are residual droplets on the ultrafiltration membrane. If so, it is determined that the current residual liquid removal is not completed, and jump back to S121 for re-detection. Otherwise, it is determined that the current residual liquid removal is completed.

[0023] Preferably, the centrifugal treatment method of step S15 further comprises the following steps: S151, centrifuging the ultrafiltration tube containing cytochrome C at 4000g, wherein the horizontal rotation is 4000g and the angular rotation is 5000g;

[0024] S152. After the centrifugation is completed, the volume of liquid filtered out at different centrifugation times is detected. If the difference between V4 and V3 is too large, it is determined that the current centrifugation result will affect the calculation of the ultrafiltration effect, and the centrifugation time of T3 is increased by 0.2T3. Otherwise, it is determined that the current centrifugation result is normal and measurement is performed.

[0025] Preferably, the volume measurement formula in step S17 is as follows:

[0026] V = W - Wg (1)

[0027] Wherein, V is the volume of the filtrate after a period of time, W is the weight of the centrifuge tube at that time, and Wg is the initial weight of the centrifuge tube.

[0028] Preferably, the calculation formula for the concentrated protein recovery rate and the calculation formula for the filtrate protein recovery rate in step S26 are as follows:

[0029] Rn= ×k×100% (2)

[0030] Rl= (3)

[0031] Wherein, Rn is the concentrated protein recovery rate of the ultrafiltration tube, Vb is the concentrated protein volume of the ultrafiltration tube, Cb is the concentrated protein concentration of the ultrafiltration tube measured by the OD value, Va is the volume of cytochrome C initially added to the ultrafiltration tube, Ca is the initial cytochrome C concentration, Rl is the filtrate protein recovery rate of the ultrafiltration tube, and k is the membrane adsorption coefficient of the current ultrafiltration tube.

[0032] By adopting the above technical solution, the following beneficial effects are achieved: 1. By integrating pretreatment, membrane integrity test, dynamic flow rate analysis and protein recovery rate determination, a complete ultrafiltration tube performance evaluation system is constructed. Specifically, the protective agent residue is removed by low-temperature standing of the buffer solution (4°C), and combined with the 0.3MPa air pressure integrity test, the interference of membrane damage or uneven pore size is quantitatively eliminated to ensure the consistency of the detection baseline. At the same time, based on multi-time point centrifugation (T1-T4) and formula (1), the filtrate volume (V=W-Wg) is calculated in real time, and the flow rate-time curve is drawn to accurately capture the membrane flux attenuation characteristics and identify blockage or concentration. The differential polarization phenomenon was further calibrated by the OD value standard curve, and the recovery rate (Rn=(Vb×Cb) / (Va×Ca)×100%) was dynamically calculated by combining formula (2). The measurement was repeated three times to eliminate the error and quantify the retention efficiency. In addition, the adaptability of the ultrafiltration tube under different rotor types was verified by differentially setting the centrifugal force of the horizontal rotation (4000g) and the angular rotation (5000g) during the centrifugal treatment process to avoid data distortion caused by centrifugal parameter deviation. This system solves the problems of detection fragmentation and data incomparability in the existing technology, and provides a unified standard for the horizontal comparison of multiple groups of ultrafiltration tubes.

[0033] 2. Furthermore, the present application draws a flow rate curve of an ultrafiltration tube and a standard curve based on OD value and cytochrome C concentration. In the curve, the protein concentration flow rate effect and protein recovery rate effect of the currently detected ultrafiltration tube can be efficiently judged, and in the process of detecting the protein concentration flow rate, in order to improve the accuracy of the experiment, the process of adding cytochrome C into the ultrafiltration tube needs to be carried out on ice. Specifically, cytochrome C is a water-soluble globular protein (molecular weight 12.4 kDa), and its activity and structure are sensitive to temperature. If the ambient temperature is too high during the experiment, it will cause the protein conformation to change, forming aggregates to block the micropores of the ultrafiltration membrane, interfering with the detection results, and affecting the reliability of the OD value measurement. Choosing to operate on ice can control the temperature of the experiment within 0-4°C, suppress the risk of thermal denaturation, ensure that the protein is in a natural folded state, and avoid the deviation of the ultrafiltration membrane retention efficiency caused by structural changes. At the same time, in step S152, the centrifugation time is extended to avoid the gap between V4 and V3 being too large, and the volume deviation can be corrected to ensure the reliability of the data and avoid the risk of experimental failure.

[0034] 3. At the same time, through the flow rate curve, protein recovery rate and membrane integrity indicators of the ultrafiltration tube, the staff can actively select the ultrafiltration tube that matches the experimental requirements according to the above indicators. Specifically, the above method can intuitively compare the effects of multiple ultrafiltration tubes horizontally, and can screen out the ultrafiltration tube model with the best performance according to the required experimental parameters to meet the needs of the experiment.

[0035] 4. In addition, in the process of testing different ultrafiltration tubes, by setting up a rotor centrifuge that is suitable for horizontal / fixed angle, there is no need to use special equipment. At the same time, standardized testing can be used to reduce the waste of resources caused by repeated experiments. At the same time, before testing the ultrafiltration tube, the integrity of the ultrafiltration membrane inside the ultrafiltration tube is tested to remove the residual liquid inside, which can further improve the accuracy of experiments and tests, make the ultrafiltration tube maintenance convenient, and extend the service life of the ultrafiltration tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A flow chart of a method for measuring a flow rate curve of an embodiment of a method for detecting an ultrafiltration effect of an ultrafiltration centrifuge tube of the present invention;

[0037] Figure 2 A flow chart of a method for measuring protein recovery rate in an embodiment of a method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube of the present invention;

[0038] Figure 3 A flow chart of an ultrafiltration membrane integrity inspection method according to an embodiment of an ultrafiltration effect inspection method for an ultrafiltration centrifuge tube of the present invention;

[0039] Figure 4 A flow chart of a method for removing residual liquid by inverted centrifugation in an embodiment of a method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube of the present invention;

[0040] Figure 5 A flow chart of a centrifugal treatment method for a sample in an embodiment of a method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube of the present invention;

[0041] Figure 6 It is a flow velocity curve diagram of different ultrafiltration tubes of an embodiment of an ultrafiltration effect detection method of an ultrafiltration centrifugal tube of the present invention;

[0042] Figure 7 A concentration-OD value standard curve diagram of an embodiment of an ultrafiltration effect detection method of an ultrafiltration centrifuge tube of the present invention;

[0043] Figure 8 The concentrated protein recovery rates of different ultrafiltration tubes in an embodiment of an ultrafiltration effect detection method of an ultrafiltration centrifuge tube of the present invention;

[0044] Fig. 9 It is the filtrate protein recovery rate of different ultrafiltration tubes in an embodiment of an ultrafiltration effect detection method of an ultrafiltration centrifugal tube of the present invention. DETAILED DESCRIPTION

[0045] Reference Figures 1 to 9 The present invention further describes an ultrafiltration effect detection method of an ultrafiltration centrifuge tube.

[0046] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0047] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0048] A method for detecting ultrafiltration effect of an ultrafiltration centrifugal tube comprises the following steps: S11, cleaning the ultrafiltration tube: adding a buffer solution into the ultrafiltration tube so that the buffer solution covers the ultrafiltration membrane in the ultrafiltration tube, and placing the ultrafiltration tube in an environment of 4° C. for a period of time T;

[0049] S12, residual liquid removal: after the T time period, the ultrafiltration tube is subjected to inverted centrifugation to remove the residual buffer in the ultrafiltration tube;

[0050] S13, component weighing: weigh the components of the ultrafiltration tube after cleaning and removing residual liquid, and measure the weight of the centrifuge tube as Wg and the weight of the filter as Wq;

[0051] S14, adding sample: adding an experimental sample into the treated ultrafiltration tube, wherein the experimental sample is cytochrome C, and the added amount thereof is V;

[0052] S15, centrifugation: centrifuging the ultrafiltration tube containing cytochrome C, and setting the centrifugation time to T1, T2, T3, and T4 respectively;

[0053] S16, finished product measurement: after centrifugation is completed, the weights of the centrifuge tubes are measured, which are W1, W2, W3, and W4;

[0054] S17, volume measurement: according to the weight of the centrifuge tube, the volume of the liquid filtered out at each centrifugation time is calculated to be V1, V2, V3, and V4 respectively;

[0055] S18. Draw a flow rate curve of each ultrafiltration tube based on the measured liquid volume.

[0056] The detection method also includes the determination of protein recovery rate, including the following steps: S21, calculating the protein recovery rate curve: multiple measurements at different gradients of cytochrome C concentration, taking the OD value at 450nm as a reference, making a standard curve, and obtaining the relationship between the OD value and the cytochrome C concentration according to the standard curve;

[0057] S22. Prepare sample solution: weigh in advance and prepare 0.25 mg / ml cytochrome C, the concentration is recorded as Ca, and the average value is obtained after three cycles;

[0058] S23, cleaning pretreatment of the ultrafiltration tube: cleaning the ultrafiltration tube and removing residual liquid;

[0059] S24, adding cytochrome C into the pre-treated ultrafiltration tube, and recording the volume of cytochrome C as Va;

[0060] S25, centrifugation: centrifuge the ultrafiltration tube containing the sample for a centrifugal time of Ta. After the Ta period, record the volume of the concentrated protein in the ultrafiltration tube as Vb. Simultaneously measure the OD value of the concentrated protein, and calculate the current concentration Cb of the concentrated protein according to the standard curve in step S21. Measure three times and take an average value.

[0061] S26. Recovery rate calculation: Calculate the recovery rate of the concentrated protein in the current ultrafiltration tube based on Va, Ca, Vb, and Cb.

[0062] Preferably, the step S11 further includes an integrity test of the ultrafiltration membrane, including the following steps: S111, injecting pure water into the ultrafiltration tube until the ultrafiltration tube is completely wetted;

[0063] S112, applying 0.3 MPa gas pressure and observing the ultrafiltration tube for a period of time T;

[0064] S113. Within the T time period, if the ultrafiltration tube does not generate continuous bubbles, the current ultrafiltration membrane is judged to be qualified; otherwise, the current ultrafiltration membrane is judged to be unqualified.

[0065] Preferably, the method of removing residual liquid by inverted centrifugation in step S12 comprises the following steps: S121, inverting the filter inside the ultrafiltration tube into a new collection tube, and centrifuging at 1000g for a period of time T;

[0066] S122. After the T time period, detect whether there are residual droplets on the ultrafiltration membrane. If so, it is determined that the current residual liquid removal is not completed, and jump back to S121 for re-detection. Otherwise, it is determined that the current residual liquid removal is completed.

[0067] Preferably, the centrifugal treatment method of step S15 further comprises the following steps: S151, centrifuging the ultrafiltration tube containing cytochrome C at 4000g, wherein the horizontal rotation is 4000g and the angular rotation is 5000g;

[0068] S152. After the centrifugation is completed, the volume of liquid filtered out at different centrifugation times is detected. If the difference between V4 and V3 is too large, it is determined that the current centrifugation result will affect the calculation of the ultrafiltration effect, and the centrifugation time of T3 is increased by 0.2T3. Otherwise, it is determined that the current centrifugation result is normal and measurement is performed.

[0069] Preferably, the volume measurement formula in step S17 is as follows:

[0070] V = W - Wg (1)

[0071] Wherein, V is the volume of the filtrate after a period of time, W is the weight of the centrifuge tube at that time, and Wg is the initial weight of the centrifuge tube.

[0072] Preferably, the calculation formula for the recovery rate of concentrated protein in step S26 is as follows:

[0073] Rn= ×k×100% (2)

[0074] Rl= (3)

[0075] Wherein, Rn is the concentrated protein recovery rate of the ultrafiltration tube, Vb is the concentrated protein volume of the ultrafiltration tube, Cb is the concentrated protein concentration of the ultrafiltration tube measured by the OD value, Va is the volume of cytochrome C initially added to the ultrafiltration tube, Ca is the initial cytochrome C concentration, Rl is the filtrate protein recovery rate of the ultrafiltration tube, and k is the membrane adsorption coefficient of the current ultrafiltration tube.

[0076] By integrating pretreatment, membrane integrity test, dynamic flow rate analysis and protein recovery rate determination, a complete ultrafiltration tube performance evaluation system was constructed. Specifically, the protective agent residue was removed by low-temperature standing of the buffer solution (4°C), and the interference of membrane damage or uneven pore size was quantitatively eliminated in combination with 0.3MPa air pressure integrity test to ensure consistent detection baseline. At the same time, based on multi-time point centrifugation (T1-T4) and formula (1), the filtrate volume (V=W-Wg) was calculated in real time, and the flow rate-time curve was drawn to accurately capture the membrane flux attenuation characteristics, identify blockage or concentration polarization phenomenon, and further The concentration was calibrated by the OD value standard curve, and the recovery rate (Rn=(Vb×Cb) / (Va×Ca)×100%) was dynamically calculated using formula (2). The measurement was repeated three times to eliminate errors and quantify the retention efficiency. In addition, the compatibility of the ultrafiltration tube with different rotor types was verified by differentially setting the centrifugal force of the horizontal rotation (4000g) and the angular rotation (5000g) during the centrifugal treatment process to avoid data distortion caused by centrifugal parameter deviation. This system solves the problems of detection fragmentation and data incomparability in the existing technology, and provides a unified standard for the horizontal comparison of multiple groups of ultrafiltration tubes.

[0077] Furthermore, the present application draws a flow rate curve of an ultrafiltration tube and a standard curve based on OD value and cytochrome C concentration. In the curve, the protein concentration flow rate effect and protein recovery rate effect of the currently detected ultrafiltration tube can be efficiently judged, and in the process of detecting the protein concentration flow rate, in order to improve the accuracy of the experiment, the process of adding cytochrome C into the ultrafiltration tube needs to be carried out on ice. Specifically, cytochrome C is a water-soluble globular protein (molecular weight 12.4kDa), and its activity and structure are sensitive to temperature. If the ambient temperature is too high during the experiment, it will cause the protein conformation to change, forming aggregates to block the micropores of the ultrafiltration membrane, interfering with the detection results, and affecting the reliability of the OD value measurement. Choosing to operate on ice can control the temperature of the experiment within 0-4°C, suppress the risk of thermal denaturation, ensure that the protein is in a natural folded state, and avoid the deviation of the ultrafiltration membrane retention efficiency caused by structural changes. At the same time, in step S152, the centrifugation time is extended to avoid the gap between V4 and V3 being too large, and the volume deviation can be corrected to ensure the reliability of the data and avoid the risk of experimental failure.

[0078] At the same time, through the flow rate curve, protein recovery rate and membrane integrity indicators of the ultrafiltration tube, the staff can actively select the ultrafiltration tube that matches the experimental requirements according to the above indicators. Specifically, the above method can intuitively compare the effects of multiple ultrafiltration tubes horizontally, and can screen out the ultrafiltration tube model with the best performance according to the required experimental parameters to meet the needs of the experiment.

[0079] Moreover, in the process of testing different ultrafiltration tubes, by setting up a rotor centrifuge that is suitable for horizontal / fixed angle, there is no need to use special equipment. At the same time, standardized testing can be used to reduce the waste of resources caused by repeated experiments. At the same time, before testing the ultrafiltration tube, the integrity of the ultrafiltration membrane inside the ultrafiltration tube is checked to remove the residual liquid inside, which can further improve the accuracy of experiments and tests, make the ultrafiltration tube maintenance convenient, and extend the service life of the ultrafiltration tube.

[0080] Specifically, for example, by adopting the above technical solution, the filtrate volumes of three different ultrafiltration tubes after different time periods are measured as shown in the following table:

[0081] Table 1 - Volume of filtrate after different ultrafiltration tubes at different times

[0082] Brand / Time 10min 20min 30min 40min A 4 8 14 14.9 B 10 14 14.5 14.9 C 12 14.5 14.8 14.9

[0083] Based on the above table, Figure 6 The flow rate curves of different ultrafiltration tubes shown are based on Table 1 and Figure 6 It can be seen that the protein concentration flow rate of brands A and B is faster than that of C;

[0084] For example, when the recovery rate of ultrafiltration tube protein is measured, a standard curve is prepared using the OD value at 450nm under different gradient cytochrome C concentrations to obtain the functional relationship between OD and concentration. Specifically, the cytochrome C has a maximum absorption peak at 520nm. By setting it at 450nm, other impurities can be effectively avoided and background interference can be reduced. At the same time, due to the high sample concentration during the experiment, the absorbance can be more sensitively responded to at 450nm, avoiding signal saturation due to excessive absorbance of cytochrome C. The relationship between the cytochrome C concentration and the OD value is shown in the following table:

[0085] Table 2 - OD values ​​at 450nm under different gradient cytochrome C concentrations

[0086] Cytochrome C concentration mg / mL 0.3750 0.7500 1.5000 3.0000 450nmOD 0.0936 0.1992 0.4066 0.8157

[0087] Based on the above table, Figure 7 The concentration-OD value standard curve is used to obtain the functional relationship between the OD value and the concentration, and the function between the concentration and the OD value is y=0.2748x-0.0076. The final protein recovery rate can be calculated by the OD value later.

[0088] Specifically, after centrifugation at 4000 g for 20 min, the concentrated protein recovery rate and filtrate protein recovery rate of different ultrafiltration tubes were obtained based on the standard curve. Figure 8 and Fig. 9As shown, it was concluded that brand B had the highest protein concentration recovery rate, followed by brand A and brand C had the worst ultrafiltration tube.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube, characterized in that: The following steps are involved: S11, ultrafiltration tube cleaning: add buffer into the ultrafiltration tube so that the buffer covers the ultrafiltration membrane in the ultrafiltration tube, and place the ultrafiltration tube in a 4°C environment for a period of time T; S12, residual liquid removal: after the T time period, the ultrafiltration tube is inverted and centrifuged to remove the residual buffer in the ultrafiltration tube; S13, component weighing: weigh the components of the ultrafiltration tube after cleaning and removing residual liquid, and measure the weight of the centrifuge tube as Wg and the weight of the filter as Wq; S14, adding sample: adding an experimental sample into the treated ultrafiltration tube, wherein the experimental sample is cytochrome C, and the added amount thereof is V; S15, centrifugation: centrifuging the ultrafiltration tube containing cytochrome C, and setting the centrifugation time to T1, T2, T3, and T4 respectively; S16, finished product measurement: after centrifugation is completed, the weights of the centrifuge tubes are measured, which are W1, W2, W3, and W4; S17, volume measurement: according to the weight of the centrifuge tube, the volume of the liquid filtered out at each centrifugation time is calculated to be V1, V2, V3, and V4 respectively; S18. Draw a flow rate curve of each ultrafiltration tube based on the measured liquid volume.

2. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The detection method also includes the determination of protein recovery rate, including the following steps: S21, calculating the protein recovery rate curve: multiple measurements at different gradients of cytochrome C concentration, taking the OD value at 450nm as a reference, making a standard curve, and obtaining the relationship between the OD value and the cytochrome C concentration according to the standard curve; S22. Prepare sample solution: weigh in advance and prepare 0.25 mg / ml cytochrome C, the concentration is recorded as Ca, and the average value is obtained after three cycles; S23, cleaning pretreatment of the ultrafiltration tube: cleaning the ultrafiltration tube and removing residual liquid; S24, adding cytochrome C into the pre-treated ultrafiltration tube, and recording the volume of cytochrome C as Va; S25, centrifugation: centrifuge the ultrafiltration tube containing the sample for a centrifugal time of Ta. After the Ta period, record the volume of the concentrated protein in the ultrafiltration tube as Vb. Simultaneously measure the OD value of the concentrated protein, and calculate the current concentration Cb of the concentrated protein according to the standard curve in step S21. Measure three times and take an average value. S26. Recovery rate calculation: Calculate the recovery rate of the concentrated protein in the current ultrafiltration tube based on Va, Ca, Vb, and Cb.

3. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The step S11 also includes an integrity test of the ultrafiltration membrane, including the following steps: S111, injecting pure water into the ultrafiltration tube until the ultrafiltration tube is completely wet; S112, applying 0.3 MPa gas pressure and observing the ultrafiltration tube for a period of time T; S113. Within the T time period, if the ultrafiltration tube does not generate continuous bubbles, the current ultrafiltration membrane is judged to be qualified; otherwise, the current ultrafiltration membrane is judged to be unqualified.

4. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The method of removing residual liquid by inverted centrifugation in step S12 comprises the following steps: S121, inverting the filter inside the ultrafiltration tube into a new collection tube, and centrifuging at 1000 g for a period of time T; S122. After the T time period, detect whether there are residual droplets on the ultrafiltration membrane. If so, it is determined that the current residual liquid removal is not completed, and jump back to S121 for re-detection. Otherwise, it is determined that the current residual liquid removal is completed.

5. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The centrifugal treatment method of step S15 further comprises the following steps: S151, centrifuging the ultrafiltration tube containing cytochrome C at 4000g, wherein the horizontal rotation is 4000g and the angular rotation is 5000g; S152. After the centrifugation is completed, the volume of liquid filtered out at different centrifugation times is detected. If the difference between V4 and V3 is too large, it is determined that the current centrifugation result will affect the calculation of the ultrafiltration effect, and the centrifugation time of T3 is increased by 0.2T3. Otherwise, it is determined that the current centrifugation result is normal and measurement is performed.

6. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 1, characterized in that: The volume measurement formula of step S17 is as follows: V = W - Wg (1) Wherein, V is the volume of the filtrate after a period of time, W is the weight of the centrifuge tube at that time, and Wg is the initial weight of the centrifuge tube.

7. The method for detecting ultrafiltration effect of an ultrafiltration centrifuge tube according to claim 2, characterized in that: The calculation formulas for the recovery rate of concentrated protein and the recovery rate of filtrate protein in step S26 are as follows: Rn= ×k×100% (2) Rl= （3） Wherein, Rn is the concentrated protein recovery rate of the ultrafiltration tube, Vb is the concentrated protein volume of the ultrafiltration tube, Cb is the concentrated protein concentration of the ultrafiltration tube measured by the OD value, Va is the volume of cytochrome C initially added to the ultrafiltration tube, Ca is the initial cytochrome C concentration, Rl is the filtrate protein recovery rate of the ultrafiltration tube, and k is the membrane adsorption coefficient of the current ultrafiltration tube.

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