Method in a bioprocess purification system

Abstract

The present invention relates to a method for controlling fraction collection of a target product 27 in a chromatography system 49 configured for cyclic purification performed on a sample containing the target product 27. The method includes determining a trigger point for collection of the target product 27 based on the presence of the target product in an outlet, setting a first time period during which eluate in a first cycle is captured based on the trigger point, evaluating the timing of the captured eluate to identify a next time period, applying the timing to capture the eluate in the elution phase of the next cycle, and collecting the captured eluate in the next cycle. The last three steps are repeated to capture the eluate in the elution phase of the next cycle until the target product 27 is no longer desired.

Description

Technical Field

[0001] The present invention relates to a method for controlling the fraction collection of a target product in a chromatography system, particularly a system having one or more chromatography columns.

Background Art

[0002] Liquid chromatography is one of the most commonly used separation principles in the analysis and production of biomolecules such as proteins and peptides. There are numerous commercial instruments and different chromatography formats available for the processing of biomolecules by chromatography.

[0003] Currently, clarified or clear feed from a bioreactor is introduced into a column capture chromatography system configured for a cyclic purifying process to extract the target product. The cyclic process includes loading the feed onto the column, washing the column, eluting the target product, and then cleaning the column before a new feed is loaded onto the column. For purification processes using small-volume columns, the elution cycle is quite short, and the window for capturing the target product during elution must be detected by a UV sensor at the outlet of the column using a fast update frequency. However, the drawback of the UV sensor is that its resolution is limited, and thus the capture of the target product during elution can be inefficient.

[0004] Therefore, there is a need to improve the process of detecting the presence of the target product during elution, particularly for small-volume columns in purification using column capture chromatography systems.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] US Patent Application No. US2014 / 0296464 [Patent Document 2] US Patent Application No. US2016 / 0288089 [Patent Document 3] International Publication No. WO2018037244 [Patent Document 4] International Publication No. WO2020 / 173862 [Patent Document 5] British Patent No. GB1909274.1 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] The object of the present disclosure is to provide a method for reducing, alleviating, or eliminating one or more of the above-mentioned drawbacks and disadvantages in the art, either alone or in any combination, as well as a device configured to execute the method and a computer program. [Means for Solving the Problems]

[0007] This object is achieved by a method as defined by the independent claims.

[0008] The advantage is that a UV detector with high resolution, i.e., a high update frequency, is not required.

[0009] Another advantage is that the yield and quality of the captured target product are improved.

[0010] Further objects and advantages can be obtained by those skilled in the art from the detailed description. [Brief Description of the Drawings]

[0011]

Figure 1

Figure 2

Figure 3a

Figure 3b

Figure 4

Figure 5a

Figure 5b

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0012] A bioprocess purification system is designed to produce and purify a target product (such as proteins, biomolecules derived from cell culture / fermentation, natural extracts, etc.) by growing cells that can express the target product in a cell culture bioreactor, and then purify the target product through a downstream purification process (also referred to as the downstream process). The downstream purification process can be any suitable process that can provide the purified target product, and the process may include one or more steps. One of the steps commonly used in the downstream purification process is chromatography. In particular, the present invention relates to a bioprocess purification system that is arranged and configured to produce and provide a purified product over a long period of time from a large volume of sample feed. The product is provided as a batch having a volume larger than the volume of the column, or the product is harvested from the bioreactor and purified by the downstream purification process while the cell culture is maintained. This type of cell culture is referred to herein as a "continuous cell culture process", and examples of such cell cultures include perfusion cell culture and chemostat cell culture.

[0013] In FIG. 1, an overview of a bioprocess purification system according to one embodiment, which is configured to purify a target product using a separation process, is illustrated. The bioprocess purification system includes a number of process steps related to cell culture 11, hold 12, capture 13, virus inactivation 14, polishing 15, and delivery 16.

[0014] In one of the disclosed embodiments of the present invention, the cell culture step 11 may be a continuous cell culture process consisting of continuous addition of nutrients over a long period of time as well as continuous removal (harvest) of products and waste. This process can be operated in perfusion to retain cells in the bioreactor, for example, by using an alternating tangential flow filtration (ATF) device. Alternatively, the bioreactor is operated without cell retention, i.e., it is a chemostat. The cell culture step may include process control not only for viable cell density (VCD) but also for nutrients and metabolites. VDC, productivity, and product quality can be controlled by adapting the components of the cell culture medium supplied to the culture or by directly adding specific components to the culture, as will be described in more detail below.

[0015] In some embodiments, the harvest containing the target product can be clarified, for example, by filtration, centrifugation, or another technique, before supplying the harvest to a downstream purification process.

[0016] The hold step 12 is an optional step depending on the needs of the process, for example, when the filter is in-line before the capture step 13. This step includes process control for weight, and the next step of this process starts when a predetermined volume value is reached, or alternatively after a specific time period, or when a predetermined mass is reached. The hold step can be used to collect a large amount of filtered feed from a perfusion cell culture.

[0017] In another embodiment of the present invention, the cell culture step is omitted, and a batch of sample feed containing the product is provided in the hold step 12 and supplied to the purification step.

[0018] In the disclosed embodiments, the downstream purification process includes three steps: capture 13, virus inactivation 14, and polishing 15. The capture step 13 may include a chromatography process in either a single chromatography column or multiple chromatography columns connected in parallel or in series or operated sequentially. A filter may be provided in-line before the capture step. The capture step includes multiple batch elutions. For example, process control using an in-line UV sensor addresses variations in feed concentration and resin volume. The next step starts when a predetermined quantity value (e.g., volume, mass, or time) is reached.

[0019] In the virus inactivation step 14, different options for virus inactivation are available depending on the needs of the process. One option is to use batch mode at low pH for 30 - 60 minutes in a hold-up tank. This step may include process control for volume, time, temperature, and pH. The next step starts when a predetermined time is reached.

[0020] The polishing step 15 may be a straight through processing (STP) by a connected batch process or continuous chromatography by a continuous loading process, or a combination thereof. The flow rate is adjusted to match the perfusion rate required by the producer cells, which means that the flow rate is determined by the preceding step. The step may desirably include process control for UV, flow, and volume, and the next step starts when a predetermined volume and quantity are reached, alternatively when a timeout is reached.

[0021] Delivery step 16 may, for example, place a virus removal step, such as a virus filter, before the ultrafiltration step. The delivery step may be used as a concentration step for batch addition of the processed harvest from the polishing step. Delivery step 16 may include continuous or batch delivery of the product and may include continuous or batch removal of waste. This step may include process control for pH, conductivity, absorbance, volume, and pressure, and delivery is achieved when a predetermined product concentration is reached within a predefined environment.

[0022] Automation layer 17 is used to handle decision points for the next step in the process. Different types of sensors (not shown), both in-line and off-line sensors, are incorporated into the process flow and monitor different parameters that can be used to supply data to automation layer 17 for handling decision points. The sensors include, but are not limited to, measurement flow only, VCD, weight, pressure, UV, volume, pH, conductivity, absorbance, etc.

[0023] Note that UV absorption is an example of a parameter that can be monitored to detect the composition of the harvested product being purified. However, other parameters acting in other frequency bands, such as IR, fluorescence emission, X-rays, etc., may also be used.

[0024] The product quality of the target product produced in the bioprocess purification system can be improved by obtaining information related to the target product during process operation or the produced target product itself. Attributes related to the product quality must be measured, and different analytical methods such as mass spectrometry MS, light scattering, size exclusion chromatography SEC, Raman spectroscopy, etc., can be used.

[0025] The cell culture system includes a bioreactor that produces a harvest containing the target product, and the cell culture process can be controlled to optimize the product quality of the target product. Examples of parameters that can be controlled in the bioreactor include temperature, aeration, agitation, etc.

[0026] Figure 2 illustrates the concept of controlling upstream / downstream processes within a bioprocess purification system. The illustration of the bioprocess purification system is simplified and includes three steps, namely, cell culture 20, separation 21, and batching 22. The target product (exemplified by the "active pharmaceutical ingredient", API in this example) is delivered after the batching step.

[0027] The cell culture step 20 has been described as including, for example, a continuous cell culture process such as the continuous addition of nutrients to a cell perfusion process with continuous harvesting of the target product and waste, or a batch of sample feed provided in a volume greater than the capacity of a single column chromatography system. The sample feed, which includes the product and waste, is considered to be the harvest that is supplied to a separation step 21 that may include one or more steps of the downstream purification process. The separation step includes a process for at least partially separating the product from the waste in the harvest, and the product is transferred to the batching 22, which is the final step, where the product is processed so that it can be delivered immediately as the API.

[0028] After the separation step, several parameters, or quality attributes, such as the composition of impurities in the target product or the amount of fragments or aggregates of the target product, can be measured using, for example, a mass spectrometer MS, or spectroscopic analysis. This information can be used to control the upstream process 23. For example, if a large amount of degraded target product is detected after separation, this can be counteracted by changing the parameters in the cell culture step, for example, by increasing the flow rate of the medium to the bioreactor to prevent the degradation of the target product molecules before they are introduced into the separation step 21. Alternatively, as detailed below, the supply of nutrients or process parameters in cell culture can be adjusted based on the measured quality attributes. Changes in the composition of the sample feed provided to the separation step 21 are detected after the column, for example, if breakthrough of the captured product is detected, and this can be counteracted by changing the amount of sample feed loaded onto the column.

[0029] The same concept can be used to control the downstream process 24. The concentration of the target product in the harvest supplied to the separation step 21 can be determined by measuring the time to load each column and the peak amount of the target product after elution. This information can be used to adjust elution based on the concentration of the target product in the harvest supplied to the separation step.

[0030] The chromatography device can be any suitable type of chromatography device, such as a conventional packed bed chromatography column, nanofiber device, membrane holder device, membrane chromatography device, monolith or chromatography cassette, radial flow column, etc.

[0031] Furthermore, the term chromatography device as used herein may also refer to one consisting of two or more chromatography units connected and operated in parallel. In one embodiment, the chromatography device is a nanofiber separation device, and the nanofiber sheet is generally mounted within a plastic device. In general terms, a chromatography device has an inlet and an outlet for liquid to pass through the device, and an affinity matrix in one or more forms such as resin, membrane, nanofiber sheet, monolith, etc. between them. The design of the device is such that the liquid is uniformly distributed within the affinity matrix and the device preferably has a low void volume.

[0032] According to one embodiment, the chromatography device is a nanofiber device as shown in U.S. Patent Application No. US2014 / 0296464, U.S. Patent Application No. US2016 / 0288089, and International Publication No. WO2018037244, all of which are incorporated herein by reference. The pore size of the nanofiber material makes it possible to provide a high flow rate that reduces the residence time to a few seconds.

[0033] The chromatography device can have a chromatography column bed volume from 0.1 mL to 5 L.

[0034] Figure 3a illustrates an exemplary cyclic capture chromatography process configured to deliver at least one product 27 from a large sample feed 25 using a purification unit 26 having a cyclic iterative purification process. In this example, the purification unit comprises only one column, the same column is used over 200 cycles, and each purification cycle includes loading a fixed amount of sample feed onto the column, washing the column, and eluting at least one captured product. However, in most real - world situations, the performance of the system deteriorates as the cycles are executed, and when the performance degrades, the column can be cleaned using an in - place cleaning procedure CIP to at least partially restore the performance of the chromatography column. Also, when the performance of the column is not properly restored by CIP, the column may have to be replaced with a new column in order to continue operating an efficient process. Methods for controlling the performance of the cyclic capture chromatography process are presented in International Publication No. WO2020 / 173862 and UK Patent No. GB1909274.1, co - pending patent applications which are incorporated herein by reference.

[0035] Figure 3b shows a schematic diagram of a chromatography system 49 including a source 50 of sample solution, a source 60 of elution buffer, a source 70 of cleaning solution and buffer / washing buffer, an inlet valve 80, a pump 90, a chromatography column 100, a detector 110, an outlet valve 120, a product receptacle 130, and a waste receptacle 140.

[0036] As described above, the source of sample solution 50 can be a continuous cell culture, optionally with intermediate clarification, etc., or a batch vessel.

[0037] The source 60 of the dissolution buffer and the source 70 of the cleaning solution may be containers of suitable size containing the relevant solutions, and one or more (or fewer) solutions may be provided according to a specific purification process. Alternatively, one or more of the solution sources 60, 70 may be provided as in-line mixing or dilution units, in which one or more of the solutions are prepared and provided as required.

[0038] The inlet valve 80 and the outlet valve 120 may be of any suitable type, typically rotary valves capable of achieving thousands of rotations with a rapid transition to a plurality of flow paths. Other examples include solenoid valves, pinch valves, air valves, etc.

[0039] The pump 90 may be a reciprocating piston pump to provide a consistent flow of the mobile phase. Other pumps may be peristaltic pumps, centrifugal pumps, diaphragm pumps, gear pumps, screw pumps, etc.

[0040] The chromatography column 100 is a microporous resin column, nanofiber device, membrane, monolith, etc.

[0041] The detector 110 may be one or more detectors capable of providing a signal indicating the presence of the target product in the fluid stream, such as a UV detector, light scattering detector, pressure sensor, diode array detector, fluorescence detector (or any spectroscopic detector...), pH meter, conductivity detector,...

[0042] The product receptacle 130 is arranged and configured to collect the product eluted from the column, which may be any suitable container. Alternatively, the chromatography system may be directly (or indirectly via a hold tank) connected to a downstream process as described above, whereby the product receptacle 130 serves as the inlet to the downstream process.

[0043] When the chromatography system 49 is operating in the circulation mode and a small amount of product is captured and eluted in multiple cycles, it becomes more important to reduce the overall hold-up volume of the chromatography flow path compared to a batch-type system having a large volume and capacity of the chromatography column. In the circulation operation, the overall process economy depends greatly on the amount of the process solution consumed, particularly on the residence amount of the process solution remaining in the system after switching to the subsequent process solution due to the hold-up volume of the system, and this residual amount is not directly required for the chromatography process. Further, it is desirable to keep the flow path between the outlet of the chromatography column 100 and the outlet valve 120 for selectively guiding the eluted product to the product receptacle 130 as short as possible to avoid the broadening of the elution peak due to diffusion, which may reduce the concentration and purity of the product.

[0044] In order to achieve high productivity in the chromatography system 49 operating in the circulation mode, it is further desirable to operate the system at a higher flow rate and backpressure level compared to the batch-type system. This is the case for nanofiber devices where the productivity can exceed 100 g / L / hr when compared with 1 - 20 g / L / hr of classical batch chromatography.

[0045] For example, a UV detector having a reading frequency of 64 times per second, at the productivity of classical batch chromatography of 6 g / L / hr, the elution peak of 3 column volumes (CV) has 4608 measurement values. At a flow rate high enough to achieve 300 g / L / hr, this decreases to 92 measurement values with a residence time of 0.48 seconds within the unit. This decrease in the number of measurement values may lead to detection delay and product loss.

[0046] A method for controlling the fraction collection of a target product in a chromatography system is disclosed. The chromatography system comprises at least one affinity chromatography separation unit and is configured for performing a cyclic purification on a sample containing the target product. The cyclic purification is defined as a purification process that is performed in successive cycles, as illustrated in FIGS. 4 and 5a. Each cycle of the purification process includes loading a feed onto the separation unit, washing the separation unit, and eluting the target product from the separation unit by providing a flow of elution fluid onto the separation unit. Fractions of the outlet flow from the separation unit containing the eluted target product are selectively directed to subsequent production steps, such as a product collection vessel or a continuous production process.

[0047] Figure 4 is a schematic diagram showing one possible cyclic operating mode of a chromatography system 49 that includes the stages of loading (L), washing (W), elution (E), and regeneration (R). The solid line represents the signal recorded by detector 110, and the purified product is represented as a sharp peak P. Below the time axis, the operating states of outlet valve 120 are shown, where D indicates that it is arranged and configured in the waste (or discard) position, and C indicates that it is arranged and configured in the product collection position. As is clear from Figure X, the time frame for collecting the elution peak when the system operates at high flow rates is very limited, and considering the steep leading and trailing edges of peak P, the timing of valve switching is very important for achieving efficient collection of the product. If the switch from D to C is too early and the switch from C to D is too late, the collected fraction is diluted and may contain more impurities in some cases. On the other hand, if the switch from D to C is too late and the switch from C to D is too early, the collected fraction is more concentrated and contains fewer impurities, but the valuable product is diverted to waste and discarded. As described above, the flow path from the outlet of chromatography column 100 to outlet valve 120 is preferably short, so that the time frame available for switching outlet valve 120 in response to the signal level recorded by detector 110 with respect to peak P may not be sufficient to achieve the appropriate timing of switching.

[0048] This method may be applicable to any system with repeated purification cycles, and since the cycles are fast and the flow rates are high, it can be difficult to use a sensor (such as a UV absorption signal or the like) to read the product concentration and directly respond to control the valve to discard the flow from the system or collect it as a purified product. An example of such a system can be a chromatography system arranged and configured to operate in a cyclic mode, but the fluid flow rate during elution is high and the flow path is between a sensor that records the product concentration and a selection device (such as a valve) arranged and configured to direct the fluid flow towards collection or waste.

[0049] Figure 5a illustrates a graph having cycles 1 to 3, which is a continuous elution cycle. Curve 30 is a UV adsorption signal corresponding to the content of the target product in the output stream during elution. The symbol "E" represents the start of the elution stage for each cycle, and ΔT0 is the time duration until the capture of the target product in cycle 1 starts at the start trigger point 31. The fraction of the eluate containing the target product is captured during the first time period ΔC0, i.e., until the end trigger point 32, as illustrated in cycle 1 on the graph denoted "Collection" in Figure 3.

[0050] Cycle 1 is the first cycle, which is usually used only for calibration. The trigger points 31 and 32 may be set by the operator before the process starts, or the start trigger point 31 may be set when the UV absorption signal increases and reaches a predetermined threshold, and the end trigger point 32 may be set when the UV absorption signal decreases and reaches a predetermined threshold (which may be the same as that in the case of the first trigger point).

[0051] Therefore, the first time period may be longer than normally allowed to ensure the capture of the target product during elution and to calculate new trigger points 33 and 34 to determine ΔT1 and the next time period ΔC1 for the next cycle. This is illustrated in cycle 1 under the graph denoted "Analysis" in Figure 5a. The start trigger point 33 and the stop trigger point 34 are identified by evaluating the timing of the amount of the target product in the outlet stream in cycle 1 and further the captured fraction of the eluate based on the captured impurities.

[0052] This timing is applied to the next cycle by waiting for ΔT1 after "E" before starting to collect the target product during the elution stage of cycle 2. The fraction of the eluate containing the target product is collected during the time period ΔC1. New trigger points 35 and 36 are then calculated for cycle 2, as illustrated in FIG. 5a, to determine ΔT2 and the next time period ΔC2 for the next cycle. The start trigger point 35 and the stop trigger point 36 are identified by evaluating the timing of the amount of target product in the outlet stream in cycle 2 and further the fraction of the eluate captured based on the impurities captured.

[0053] This timing is applied to the next cycle by waiting for ΔT2 after "E" before starting to collect the target product during the elution stage of cycle 3. The fraction of the eluate containing the target product is collected during the time period ΔC2. New trigger points 37 and 38 are then calculated for cycle 3, as illustrated in FIG. 5, to determine ΔT3 and the next time period ΔC3 for the next cycle. The start trigger point 37 and the stop trigger point 38 are identified by evaluating the timing of the amount of target product in the outlet stream in cycle 3 and further the fraction of the eluate captured based on the impurities captured.

[0054] The calculated start trigger points 33, 35, and 37 are generally denoted as T1, and the calculated stop trigger points 34, 36, 38 are generally denoted as T2.

[0055] FIG. 5b is a diagram illustrating the modified timing for successive cycles, where the timing of the successive cycles is calculated based on the yield and amount of impurities captured in the current cycle. As illustrated, during the first cycle "Cycle 1", elution is captured at the initial time period ΔC0, and the captured fraction of the eluate can be used for calibration purposes to determine the timing of the eluate in the elution stage for the next cycle. In this example, trigger points T1 and T2 are selected such that elution peak 39 is within the time period ΔC0 and 100% of the target product is ensured to be captured along with the impurities.

[0056] To reduce the amount of impurities, a new trigger point is applied, the time period ΔC1 for the next cycle "Cycle 2" is calculated, and the fraction of the eluate containing the target product is collected during that time period. This process is repeated for "Cycle 3", and during "Cycle 4", the amount of the target product in the fraction of the eluate collected at the time period ΔC3 may be reduced, for example, to 95% of the amount of the target product, while the amount of impurities is less compared to the previous cycle.

[0057] An important part of the present invention is to identify the starting point for the collection of the target product. However, there are several options for determining the optimal stopping point. According to some embodiments, the stopping point is determined based on the duration from the starting point, which is adapted over time by peak analysis. The duration can be actively controlled by determining the duration from the starting point to the peak intensity and estimating the stopping point based thereon, i.e., there is a level of pre-determination of the stopping point that may be sufficient to have a more direct control method.

[0058] Accordingly, a method for controlling the fraction collection of the target product includes determining, at the start of an elution stage that is repeatedly cycled, a trigger point for the collection of the target product regarding the presence of the target product in the outlet stream, for example, using a UV detector.

[0059] The processes described in connection with FIGS. 5a and 5b may be used in any type of chromatography system, i.e., not only in a single column system, and there are repeated purification cycles, and it should be noted that the cycles are fast and the flow rates are high. In such a system, it can be difficult to use a sensor (such as a UV absorption signal) to read the product concentration and, in direct response thereto, control a valve to discard the flow from the system or collect it as a purified product.

[0060] Table 1 below exemplifies the residence times for separation units having different residence times and the corresponding resolution of a UV detector (i.e., the number of readings per elution peak). Thus, for a separation unit with a short residence time, it is difficult to monitor the elution peak and adjust the timing of the capture stage based solely on the signal from the UV detector.

[0061] [Table 1]

[0062] CV is the abbreviation for Column Volume, the internal volume of the separation unit. In this example, the elution peak is set to a width of 4CV. From a normal bead column (at 6 times the recommended residence time), 14,400 data points per elution peak are expected as compared to a separation unit operating at a residence time of 1 second having 40 data points for the same elution peak.

[0063] FIG. 6 illustrates a method for controlling the fraction collection of a target product in a chromatography system having at least one affinity chromatography separation unit (e.g., a column). The chromatography system is configured for a cyclic purification performed on a sample containing the target product, and each cycle of the purification process includes loading a feed onto each separation unit, washing each separation unit, and eluting the target product from each separation unit by sending a flow of elution fluid over each separation unit and selectively directing a fraction of the outlet flow from each separation unit containing the eluted target product to a subsequent production step.

[0064] The method for controlling the fraction collection of the target product further includes the following.

[0065] Based on trigger points 31 and 32, a first time period ΔC0 is set, 41, during which a fraction of the eluate in the first cycle is captured, 42.

[0066] The timing of the captured eluate is evaluated, 43, to identify the next time periods ΔC1, ΔC2, ΔC3.

[0067] That timing is applied, 44, to capture a fraction of the eluate in the elution stage of the next cycle.

[0068] The captured fraction of the eluate is collected in the next cycle for collection, 45. Note that the term "collection" covers both the occasion when the fraction is collected in a collection vessel and when the fraction is directed to a subsequent production step. Ideally, the fraction contains the target product, but in practice, the eluted target product exits the column as a "gradient peak", so there is always a balance between collecting all of the target product (yield) and avoiding the collection of other components (impurities) or reducing the eluate concentration.

[0069] In step 46, if it is determined that more target product is to be collected, the process continues by repeating steps 43 - 45 in the purification process to capture the fraction of the target product in the elution stage of the next cycle.

[0070] Otherwise, the process ends at step 47.

[0071] According to some embodiments, the eluate captured in the first cycle "Cycle 1" in step 42 is used for calibration purposes to determine the timing of the eluate in the elution stage of the next cycle "Cycle 2". According to some embodiments, the eluate captured in the first cycle is either collected or discarded as waste to reduce the risk of impurity contamination during capture.

[0072] According to some embodiments, the chromatography system is a single column chromatography system.

[0073] According to some embodiments, the method further includes recording the presence of the target product in the outlet stream from each column over time, for example, as an elution curve 30, and the step of determining the trigger point further includes determining a start time T1 and a stop time T2 for target product collection.

[0074] According to some embodiments, the presence of the target product is recorded as an elution curve over time, and the start of the elution stage is determined from the elution curve 30.

[0075] The present invention also relates to a chromatography system comprising at least one affinity chromatography separation unit configured for cyclic purification performed on a sample containing a target product, and a control unit configured to control each cycle of the purification process, and the control unit is further configured to perform the method described in relation to FIG. 6.

[0076] The method described above can be implemented by a computer program for controlling a bioprocess purification system. The computer program includes instructions that, when executed on at least one processor, cause the at least one processor to execute the method according to the different variations described in connection with FIG. 6. A computer program for controlling a bioprocess purification system is stored in a computer-readable storage medium and carried by the computer-readable storage medium.

[0077] In one embodiment, the switching of the outlet valve 120 is controlled by the following combined algorithm. When the detector signal is higher than a predetermined level before T1, the valve is opened, When the detector signal is lower than a predetermined level before T2, the valve is closed.

Explanation of Signs

[0078] 11 Cell culture 12 Hold 13 Capture 14 Virus inactivation 15 Polishing 16 Delivery 17 Automation layer 20 Cell culture 21 Separation 22 Batch 23 Upstream process 24 Downstream process 25 Sample feed 26 Purification unit 27 Target product 31 Start trigger point 31 and 32 Trigger points 33 and 34 Trigger points 35 Start trigger point 36 Stop trigger point 37 and 38 Trigger points 49 Chromatography system 50 Source of sample solution 60 Source of elution buffer Source of purification solution and buffer / washing buffer 80 Inlet valve 90 Pump 100 Chromatography column 110 Detector 120 Outlet valve 130 Product receptacle 140 Waste liquid receptacle

Claims

1. A method for controlling fraction collection of a target product (27) in a chromatography system (49) comprising at least one affinity chromatography separation unit, wherein the chromatography system (49) is configured for cyclic purification performed on a sample containing the target product (27), and each cycle of the cyclic purification comprises a step of loading a feed (25) onto the separation unit, a step of washing the separation unit, a step of eluting the target product from the separation unit by controlling fraction collection by sending a flow of elution fluid over the separation unit and selectively directing a fraction of the outlet flow from the separation unit containing the eluted target product to a subsequent production step, the method for controlling fraction collection of the target product comprises a step of recording the presence of the target product (27) in the outlet flow from each column over time, a step of determining a trigger point for target product collection regarding the presence of the target product (27) in the outlet flow, wherein for each cycle, regarding the start E of the elution phase, the trigger point includes a start time T1 and a stop time T2 for target product collection, the method for controlling fraction collection of the target product comprises a) Based on the trigger point, the fraction of the eluate in the first cycle is captured (42), and the first time period ΔC ０ is set (41), and b) evaluating the timing of the captured eluate (43) and identifying a trigger point and corresponding next time period ΔC １ , ΔC ２ , ΔC ３ ; and c) the timing ΔC １ , ΔC ２ , ΔC ３ is applied (44), and the step of capturing and collecting the fraction of the eluate in the elution stage of the next cycle e) a step of repeating steps b) to c) in the purification process. A method.

2. The eluate captured in the first cycle is used for calibration purposes to determine the timing of the elution in the elution phase for the next cycle, and / or The eluate captured in the first cycle is collected. The method according to claim 1.

3. The chromatography system (49) is a single-column chromatography system. The method according to claim 1 or 2.

4. The presence of the target product (27) is recorded as an elution curve over time, and the start of the elution phase is determined from the elution curve. The method according to any one of claims 1 to 3.

5. A chromatography system (49) composed of at least one affinity chromatography separation unit, wherein the chromatography system is configured in accordance with a cyclic purification process performed on a sample containing a target product (27), and includes a control unit configured to control each cycle of the purification process, and the process includes loading a feed onto the separation unit; washing the separation unit; eluting the target product from the separation unit by sending a flow of elution fluid over the separation unit and controlling fraction collection by selectively directing a fraction of the outlet flow from the separation unit containing the eluted target product to a subsequent production step; The control unit records the presence of the target product (27) in the outlet flow from each column over time; determines a trigger point for target product collection regarding the presence of the target product (27) in the outlet flow, and for each cycle, the trigger point includes a start time T1 and a stop time T2 regarding the start E of the elution stage for target product collection; is configured as such; A method for controlling fraction collection of a target product a) Based on the trigger points (31, 32), the fraction of the eluate in the first cycle is captured (42), and the first time period ΔC ０ is set (41); and b) evaluating the timing of the captured eluate (43) and identifying trigger points (33, 34, 35, 36, 37, 38) and corresponding next time periods ΔC １ , ΔC ２ , ΔC ３ ; c) said timing ΔC １ , ΔC ２ , ΔC ３ are applied (44), and capturing and collecting the fraction of the eluate in the elution stage of the next cycle d) further includes repeating steps b) to c) in the purification process. A chromatography system (49). **Claim 6** The eluate captured in the first cycle is used for calibration purposes, and the control unit is further configured to determine the timing of the elution in the elution stage for the next cycle. The chromatography system (49) according to claim 5. **Claim 7** The control unit is configured to collect the eluate captured in the first cycle. The chromatography system (49) according to claim 5 or 6. **Claim 8** The chromatography system is a single-column chromatography system. The chromatography system (49) according to any one of claims 5 to 7. **Claim 9** The control unit is further configured to record the presence of the target product (27) as an elution curve over time, and the start of the elution stage is determined from the elution curve. The chromatography system (49) according to claim 5. **Claim 10** A computer program for controlling fraction collection in a chromatography system (49), which, when executed on at least one processor, includes instructions for causing the at least one processor to execute the method according to any one of claims 1 to 4.

11. A computer-readable storage medium storing a computer program for controlling fraction collection in the chromatography system (49) according to claim 10.

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