Method and System for Separating Biomolecules
A separation system, and an elution arrangement to be provided in a separation system, for separating a biomolecule from a cell culture are provided.
This application is a divisional of and claims the priority benefit of U.S. application Ser. No. 16/470,607, Filed Jun. 18, 2019, which claims the priority benefit of PCT/EP2017/0084620 filed on Dec. 27, 2017 which claims priority benefit of Great Britain Application Nos. 1622307.5, 162304.2, and 1622305.9, which were filed Dec. 28, 2016. The entire contents of which are hereby incorporated by reference herein.
TECHNICAL FIELD OF THE INVENTIONThe present invention relates to a separation system and to a method in a separation system for separating a biomolecule from a cell culture.
RELATED ARTTraditionally a wanted biomolecule is separated from a cell culture by first clarifying the cell culture, i.e. remove cells, other biomolecules and different rest products. The clarifying usually comprises for example ultracentrifugation, depth filtration and sterile filtration. After the clarifying step further purification is needed, for example by chromatography. This is in many ways a complicated, time consuming and expensive process.
SUMMARYIt is an object of the present invention to provide an improved method and system for separating biomolecules from a cell culture.
This is achieved in a method, system and elution arrangement according to the independent claims.
In one aspect of the invention a method in a separation system for separating a biomolecule from a cell culture is provided. The method comprises the steps of:
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- providing a feed from a cell culture comprising said biomolecule to a magnetic separator and providing to the magnetic separator magnetic beads comprising ligands capable of binding this biomolecule;
- separating by the magnetic separator said magnetic beads with bound biomolecules from the rest of the feed;
- forwarding said magnetic beads as a slurry with an added buffer to an elution cell;
- eluting the bound biomolecules in the elution cell.
In another aspect of the invention a separation system for separating a biomolecule from a cell culture is provided. Said system comprises:
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- a magnetic separator comprising an inlet for receiving a feed from the cell culture comprising said biomolecule and for receiving magnetic beads comprising ligands capable of binding this biomolecule, said magnetic separator being configured for separating said magnetic beads with said bound biomolecule from the rest of the feed; and
- an elution arrangement comprising an elution cell, said elution cell comprising an elution cell inlet in connection with an outlet from the magnetic separator for receiving said separated magnetic beads as a slurry with buffer from the magnetic separator, wherein said elution arrangement is configured for eluting the biomolecule from the magnetic beads.
In further another aspect of the invention an elution arrangement configured for being connected in a separation system as described above is provided. Said elution arrangement comprises an elution cell, said elution cell comprising an elution cell inlet configured for being connected to an outlet from a magnetic separator for receiving magnetic beads as a slurry with buffer from the magnetic separator, wherein said elution arrangement is configured for eluting a biomolecule from the magnetic beads.
Hereby a more effective method and system for separating biomolecules are achieved. The separation process is much easier, faster and cheaper than traditional separation processes. When cells and solid contaminants are separated from the magnetic beads in the magnetic separator, the beads are transferred to a separate elution arrangement with low dead volume to facilitate high concentration and low elution volume of target biomolecule. The system including an elution arrangement and easy transport and capture of the magnetic beads will increase the effectivity of the system since two or more separation processes can be run in parallel.
A closed and aseptic system is possible and two or three separation processes can be run in parallel in the system. The magnetic beads can be reused for a next separation cycle. The elution can be performed in a smaller volume than in the magnetic separator which will improve effectivity. A batch uptake of biomolecule will give a more homogenous uptake of target onto the beads in comparison to traditional chromatography. In traditional chromatography, the concentration of the target is high at the inlet of the column and aggregate formation of target may occur. If the target is evenly distributed on the resin bed there is a lower risk for aggregation and precipitation at elution.
In one embodiment of the invention the magnetic beads are forwarded from the elution cell for reuse in the magnetic separator.
In one embodiment of the invention a new portion of feed from the cell culture and magnetic beads are provided into the magnetic separator while a previous portion is in the elution cell, whereby at least two portions of magnetic beads are circulating in the separation system. Hereby an effective process is achieved.
Further embodiments are described in the dependent claims.
According to the invention a method and a separation system for separating a biomolecule from a cell culture is provided. Furthermore, an elution arrangement configured for being connected to a separation system is provided. The method comprises the steps of:
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- providing a feed from a cell culture comprising said biomolecule to a magnetic separator and providing magnetic beads comprising ligands capable of binding this biomolecule to the magnetic separator;
- separating by the magnetic separator said magnetic beads with bound biomolecules from the rest of the feed;
- forwarding said magnetic beads as a slurry with an added buffer to an elution cell;
- eluting the bound biomolecules in the elution cell.
In some embodiments, the method further comprises forwarding the magnetic beads from the elution cell for reuse in the magnetic separator.
All three separation systems 1; 101; 201 also comprises an elution arrangement 8; 108; 208 comprising an elution cell 7; 107; 207. The elution cell comprises an elution cell inlet 7a; 107a; 207a, in connection with an outlet 5b; 105b; 205b from the magnetic separator 5; 105; 205 for receiving said separated magnetic beads as a slurry with buffer from the magnetic separator. When forwarding said magnetic beads from the magnetic separator 5; 105; 205 to the elution arrangement buffer is suitably added to the magnetic separator for allowing the magnetic beads to be flowed to the elution arrangement 8; 108; 208.
The elution arrangement 8; 108; 208 is configured for eluting the biomolecule from the magnetic beads. Hereby the elution arrangement 8; 108; 208 comprises a buffer providing arrangement 8a; 108a; 208a connected to an elution cell inlet 7a; 107a′; 207a′ and a collection arrangement 8b; 108b; 208b connected to an elution cell outlet 7b; 107b′; 207b′. The elution arrangement is configured for performing elution by providing elution buffer from the buffer providing arrangement and collecting eluate in the collection arrangement and possibly also performing strip and cleaning in place, CIP, by providing cleaning buffer from the buffer providing arrangement and collect waste in the collection arrangement and possibly also performing equilibration of the magnetic beads in the elution cell by providing equilibration buffer from the buffer providing arrangement.
In some embodiments the elution cell 107, 207 comprises two inlets 107a, 107a′; 207a, 207a′ and two outlets 107b, 107b′; 207b, 207b′. Actually, also the elution cell 7 in the separation system shown in
In the embodiment shown in
In the embodiment shown in
The elution cell 107; 207 comprises in the embodiment shown in
The elution cell 7; 107; 207 comprises a retaining arrangement 502a-c,f-h for keeping the magnetic beads within the elution cell and allowing excess buffer to escape from the elution cell. These retaining arrangement and further details of the elution cells are shown in
In the embodiments shown in
The separation systems 1; 101 shown in
The capturing cells 9; 109 shown in
In the separation systems 1; 101; 201 according to the invention a new portion of feed from the cell culture 3; 103; 203 and magnetic beads can be provided into the magnetic separator 5; 105; 205 while a previous portion is in the elution cell 7; 107; 207. Hereby at least two portions of magnetic beads can be used in the separation system simultaneously and processes for separating biomolecules can be made more effective.
In the embodiments shown in
For all the embodiments shown in
The separation system 101 shown in
In some embodiments, the draining arrangement in the intermediate cell 111 is constructed as the retaining arrangement 502 b-c, f, h and comprises a magnet for keeping the magnetic beads inside the intermediate cell 111 by magnetic force while draining the intermediate cell from buffer.
In another aspect of the invention an elution arrangement 8; 108; 208 is provided which is configured for being connected in a separation system as described above.
The volume of the elution cell 307a can either be of a size such that all the content received from the magnetic separator, i.e. magnetic beads and buffer, called slurry of magnetic beads, can fit into the elution cell or the volume can be smaller. If the elution cell 307a has a smaller volume the magnetic beads can be packed in the elution cell by flow packing, i.e. flowing the slurry of magnetic beads through the elution cell 307a. A retaining arrangement 502a needs to be provided in the elution cell 307a for keeping the magnetic beads within the elution cell 307a while allowing the buffer to escape out from the elution cell. The retaining arrangement 502a can be a for example a filter, also called a frit or a sinter provided such that it covers the outlets 311a, 311b from the elution cell 307a. Another possible retaining arrangement could be a pinch valve just pinching the outlet(s) or a magnetic force provided to the outlet(s) or to a part of the elution cell close to the outlet(s). If the internal volume of the elution cell is smaller than the total volume of slurry of magnetic beads to be received from the magnetic separator the volume of the elution cell can in one embodiment of the invention be less than half the volume of the total amount of the slurry of the magnetic beads to be received. Hereby the flow packing will provide a bed of magnetic beads within the elution cell with a suitable void volume, for example less than 60%. If on the other hand the elution cell 307a has a larger internal volume arranged for comprising all the received slurry of magnetic beads for example gravitational force or magnetic force could be used for providing a packed bed of magnetic beads suitable for the elution process. Magnetic force could be provided to a part of the elution cell close to the outlet, as for example shown in
In
In
A1: Providing a feed from a cell culture 3 to a capturing cell 9. Said feed comprises a biomolecule to be separated. Said capturing cell 9 comprises magnetic beads comprising ligands capable of binding this biomolecule. In the capturing cell 9 the biomolecule will bind to the magnetic beads. Possibly mixing is provided in the capturing cell 9 for improving binding. In an alternative embodiment the cell culture is provided directly into the magnetic separator instead of into the capturing cell. In this embodiment, the capturing will take place inside the magnetic separator instead of in the capturing cell and the capturing cell is only an intermediate step for storing the magnetic beads.
A3: Providing the cell culture and the magnetic beads from the capturing cell 9 to the magnetic separator 5.
A5: Separating out the magnetic beads with bound biomolecule in the magnetic separator by applying a magnetic force as described above. This step also includes washing out other particles of the feed by using the washing arrangement 13 as described above. Possibly one or more washing cycles are provided where a washing buffer is provided into the magnetic separator when the magnetic beads are bound to parts of magnetic material. The washing buffer is collected outside the magnetic separator and finally a buffer is added to the magnetic separator and the magnetic force is released.
A7: Forwarding the magnetic beads and the buffer in a slurry to the elution cell 7. Before elution the magnetic beads can be packed into a bed as described above—for example by magnetic force, gravitational force, flow packing or by use of an adaptor.
A9: Eluting the bound biomolecule from the magnetic beads by providing an elution buffer from the buffer providing arrangement 8a and collecting the eluted biomolecule in the collection arrangement 8b. Possibly the elution cell 7 and the magnetic beads are also cleaned in place, CIP, by providing a CIP buffer to the elution cell 7 from the buffer providing arrangement 8a and collect the CIP buffer in the collection arrangement 8b. And possibly the magnetic beads are also equilibrated by providing an equilibration buffer from the buffer providing arrangement 8a and collect the equilibration buffer in the collection arrangement 8b. Possibly strip is also performed as described above.
A11: Forwarding the magnetic beads to the capturing cell 9. This step can include pushing out the magnetic beads by forcing an adaptor towards the outlet of the elution cell. It could also include resuspending the bed of magnetic beads in the elution cell by providing an amount of buffer into the elution cell and then the slurry of magnetic beads and buffer could be pumped or pushed out from the elution cell and into the intermediate container 111. Another alternative or complementary can be to remove a retaining arrangement such as a bottom filter or magnetic force keeping the magnetic beads inside the elution cell and pumping or pushing the magnetic beads to the capturing cell 109.
And then the process can continue by adding new cell culture to the capturing cell 9. With this set up it is possible to have two or even three portions of magnetic beads circulating in the system as described above. Hereby one portion is in the magnetic separator 5 while one portion is in the elution cell 7 and one portion can at the same time be in the capturing cell 9 Hereby an effective process for separating a biomolecule is achieved. The system shown in
B1: Providing a feed from a cell culture 103 to a capturing cell 109. Said feed comprises a biomolecule to be separated. Also providing to the capturing cell 109 magnetic beads from a magnetic beads storage tank 121 and/or from an intermediate cell 111 provided in the system. If new magnetic beads need to be provided by some reason instead of reusing the magnetic beads from a previous separation these new magnetic beads can be provided from magnetic beads storage tank 121. The magnetic beads comprise ligands capable of binding the biomolecule to be separated. In the capturing cell 109 the biomolecule will bind to the magnetic beads. Possibly mixing is provided in the capturing cell 109 for improving binding.
B3: Providing the cell culture and the magnetic beads from the capturing cell 109 to the magnetic separator 105.
B5: Separating out the magnetic beads with bound biomolecule in the magnetic separator by applying a magnetic force and washing as described above in relation to
B7: Forwarding the magnetic beads and the buffer in a slurry to the elution cell 107 and possibly packing the magnetic beads as described above.
B9: Eluting the bound biomolecule from the magnetic beads and possibly CIP, equilibrate and strip as described above in relation to
B11: Forwarding the magnetic beads from the elution cell 107 to an intermediate container 111. This step can include pushing out the magnetic beads by forcing an adaptor towards the outlet of the elution cell. It could also include resuspending the bed of magnetic beads in the elution cell by providing an amount of buffer into the elution cell and then the slurry of magnetic beads and buffer could be pumped or pushed out from the elution cell and into the intermediate container 111. Another alternative or complementary can be to remove a retaining arrangement such as a bottom filter or magnetic force keeping the magnetic beads inside the elution cell and pumping or pushing the magnetic beads to the capturing cell 109.
B13: Optionally draining buffer from the slurry of magnetic beads if buffer was added during the step of forwarding B11 the magnetic beads from the elution cell to the intermediate container. The draining can in one embodiment be provided by providing a magnetic force to the intermediate container 111 which will keep the magnetic beads within the container while buffer can be drained through an outlet 123 to a waste container 125.
B15: Providing the magnetic beads to the capturing cell 109 for reuse in a next separation process. However, in one embodiment parts or all of the magnetic beads could at some stage of the process be taken out from the system to the waste container 125 and be replaced by new magnetic beads provided to the capturing cell 109 from the magnetic beads storage tank 121.
C1: Providing a feed directly from a cell culture 203 in to the magnetic separator 205. Magnetic beads have already been provided into the cell culture 203 in this embodiment and the cell culture could thus also be called a capturing cell 209. Said magnetic beads have a ligand binding to the biomolecule to be separated. Alternatively, the magnetic beads could instead be provided directly into the magnetic separator 205 and the biomolecule will bind to the magnetic beads inside the magnetic separator, i.e. cell culture and magnetic beads are provided into the magnetic separator individually.
C3: Separating out the magnetic beads with bound biomolecule in the magnetic separator by applying a magnetic force and washing as described above in relation to
C5: Forwarding the magnetic beads and the buffer in a slurry to the elution cell 207 and possibly packing the magnetic beads as described above.
C7: Eluting the bound biomolecule from the magnetic beads and possibly CIP, equilibrate and strip as described above in relation to
C9: Forwarding the magnetic beads from the elution cell 207 to a storage vessel 215. This step can include pushing out the magnetic beads by forcing an adaptor towards the outlet of the elution cell. It could also include resuspending the bed of magnetic beads in the elution cell by providing an amount of buffer into the elution cell and then the slurry of magnetic beads and buffer could be pumped or pushed out from the elution cell and into the storage vessel 215. Another alternative or complementary can be to remove a retaining arrangement such as a bottom filter or magnetic force keeping the magnetic beads inside the elution cell and pumping or pushing the magnetic beads to the storage vessel 215.
The method as described in the flow chart of
In
Fluid flow paths for sample liquid with or without magnetic beads are shown by double lines
Fluid flow paths for introduction of fluids and for removal of liquids from the circuit are shown by single lines.
In the system shown in
Then loop 4d-4i until the bioprocess reactor, BP, is empty.
Then repeat 5d, 5e, 5f until batch is completed.
To achieve highest possible concentration, elution is performed in batch mode by contacting the beads with a predetermined volume of elution buffer during a predetermined time. The elution buffer including eluted target sample is collected in elution vial. Then the magnetic beads (including remaining target sample) are forwarded to the capture cell without CIP.
In these systems, the magnetic beads (and the cells) do not have to pass through any pump where there is an increased chance that they are damaged. The general process disclosed in the figures may be applied also using pumps in the loop in case it can be verified that beads are not damaged or in case debris from damaged beads is ok in the process. Some steps in the loop may be facilitated by gravity by placing one cell above the subsequent cell. E.g. the elution cell, EC, may be arranged above the capturing cell, CC, in order to facilitate transport of magnetic beads from the elution cell, EC, to the capturing cell, CC, and to reduce the amount of buffer needed for this transport.
Claims
1. A separation system for separating a biomolecule from a cell culture, wherein said system comprises:
- a magnetic separator comprising an inlet for receiving a feed from the cell culture comprising said biomolecule and for receiving magnetic beads comprising ligands capable of binding this biomolecule, said magnetic separator being configured for separating said magnetic beads with said bound biomolecule from the rest of the feed; and
- an elution arrangement comprising an elution cell, said elution cell comprising an elution cell inlet in connection with an outlet from the magnetic separator for receiving said separated magnetic beads as a slurry with buffer from the magnetic separator, wherein said elution arrangement is configured for eluting the biomolecule from the magnetic beads.
2. The separation system according to claim 1, wherein said elution cell further comprises an elution cell outlet configured for forwarding the magnetic beads from the elution cell for reuse in the magnetic separator.
3. The separation system according to claim 1, further comprising:
- a capturing cell connected to the inlet of the magnetic separator and comprising a cell culture inlet for receiving a feed from a cell culture and at least one magnetic bead inlet for receiving magnetic beads, said capturing cell being configured for mixing the feed from the cell culture and the magnetic beads thus allowing the specific biomolecule to bind to the magnetic beads before forwarding it to the magnetic separator.
4. The separation system according to claim 1, wherein the magnetic separator further comprises parts of magnetic material inside the magnetic separator which parts attract the magnetic beads when a magnetic field is applied, and said magnetic separator being configured for releasing the magnetic field when the magnetic beads are to be forwarded to the elution cell, said magnetic separator further comprising a washing arrangement configured for washing out other components from the magnetic separator than those magnetically bound to the parts of magnetic material.
5. The separation system according to claim 4, wherein said washing arrangement comprises at least one wash buffer providing arrangement connected to a pump and to the inlet of the magnetic separator possibly via a capturing cell and a wash buffer collection arrangement connected to the outlet of the magnetic separator, said washing arrangement being configured for flowing washing buffer through the magnetic separator for washing out other components of the feed than those bound to the magnetic parts.
6. The system according to claim 1, wherein said elution arrangement further comprises a buffer providing arrangement connected to an elution cell inlet and a collection arrangement connected to an elution cell outlet and wherein said elution arrangement is configured for performing elution by providing elution buffer from the buffer providing arrangement and collecting eluate in the collection arrangement and possibly also performing cleaning in place, CIP, by providing cleaning buffer from the buffer providing arrangement and collect waste in the collection arrangement and possible also performing equilibration of the magnetic beads in the elution cell by providing equilibration buffer from the buffer providing arrangement.
7. The separation system according to claim 1, wherein a new portion of feed from the cell culture and magnetic beads are provided into the magnetic separator while a previous portion is in the elution cell, whereby at least two portions of magnetic beads are circulating in the separation system.
8. The separation system according to claim 7, wherein a new portion of feed from the cell culture and magnetic beads are provided into the magnetic separator while one previous portion is in the elution cell and one previous portion is in a capturing cell, whereby three portions of magnetic beads are circulating in the separation system.
9. The separation system according to claim 1, wherein the cell culture, the magnetic separator and the elution arrangement are connected by pre-sterilized, flexible tubing and aseptic connectors, closed system.
10. The separation system according to claim 1, wherein the elution cell further comprises an elution cell first outlet for forwarding the magnetic beads for reuse in the magnetic separator and an elution cell second outlet for collecting eluate and waste in a collection arrangement.
11. The separation system according to claim 1, wherein the elution cell further comprises an elution cell first inlet for receiving magnetic beads from the magnetic separator and an elution cell second inlet for receiving elution buffer, cleaning in place, CIP, buffer and equilibration buffer from a buffer providing arrangement.
12. The separation system according to claim 1, wherein said elution cell further comprises a retaining arrangement for keeping the magnetic beads within the elution cell and allowing excess buffer to escape from the elution cell.
13. The separation system according to claim 13, wherein said retaining arrangement is a pinch, a magnetic force or a filter.
14. The separation system according to claim 1, wherein the elution cell further comprises an adaptor for packing the magnetic beads in the elution cell and a retaining arrangement configured for keeping the magnetic beads inside the elution cell while allowing other buffer to escape from the elution cell.
15. The separation system according to claim 14, wherein the adaptor further is configured to be used for forwarding the magnetic beads for reuse in the magnetic separator by pushing the adaptor towards an outlet of the elution cell and removing a retaining arrangement configured for keeping the magnetic beads inside the elution cell.
16. The separation system according to claim 1, wherein the elution cell further comprises an adaptor which is positioned at a start positon in the elution cell when a slurry of magnetic beads starts to fill the elution cell from a bottom inlet of the elution cell, said start position being closer to the bottom inlet than an end position, which end position corresponds to the position of the adaptor when the filling of magnetic beads into the elution cell is completed, said adaptor keeping a force towards the flow direction of the slurry and allowing buffer to escape though the adaptor during the filling.
17. The separation system according to claim 1, further comprising an intermediate cell connected to an elution cell outlet and configured for receiving the magnetic beads form the elution cell, said intermediate cell further being configured for forwarding the magnetic beads for possible reuse in the magnetic separator.
18. The separation system according to claim 17, wherein said intermediate cell comprises a draining arrangement for removing excess buffer from the intermediate cell.
19. The separation system according to claim 18, wherein the draining arrangement comprises a magnet for keeping the magnetic beads inside the intermediate cell by magnetic force while draining the intermediate cell from buffer.
20. An elution arrangement configured for being connected in a separation system according to claim 1, said elution arrangement comprising an elution cell, said elution cell comprising an elution cell inlet configured for being connected to an outlet from a magnetic separator for receiving magnetic beads as a slurry with buffer from the magnetic separator, wherein said elution arrangement is configured for eluting a biomolecule from the magnetic beads.
21. The elution arrangement according to claim 20, wherein said elution cell further comprises an elution cell outlet configured for forwarding the magnetic beads from the elution cell for reuse in the magnetic separator.
22. The elution arrangement according to claim 20, wherein said elution arrangement further comprises a buffer providing arrangement connected to an elution cell inlet and a collection arrangement connected to an elution cell outlet and wherein said elution arrangement is configured for performing elution by providing elution buffer from the buffer providing arrangement and collecting eluate in the collection arrangement and also performing cleaning in place, CIP, by providing cleaning buffer from the buffer providing arrangement and collect waste in the collection arrangement and also performing equilibration of the magnetic beads in the elution cell by providing equilibration buffer from the buffer providing arrangement.
23. The elution arrangement according to claim 20, wherein the elution cell further comprises an elution cell first outlet for forwarding the magnetic beads for reuse in the magnetic separator and an elution cell second outlet for collecting eluate and waste in a collection arrangement.
24. The elution arrangement according to claim 20, wherein the elution cell further comprises an elution cell first inlet for receiving magnetic beads from the magnetic separator and an elution cell second inlet for receiving elution buffer, cleaning in place, CIP, buffer and equilibration buffer from a buffer providing arrangement.
25. The elution arrangement according to claim 20, wherein said elution cell further comprises a retaining arrangement for keeping the magnetic beads within the elution cell and allowing excess buffer to escape from the elution cell.
26. The elution arrangement according to claim 25, wherein said retaining arrangement is a pinch, a magnetic force or a filter.
27. The elution arrangement according to claim 20, wherein the elution cell further comprises an adaptor for packing the magnetic beads in the elution cell and a retaining arrangement configured for keeping the magnetic beads inside the elution cell while allowing other buffer to escape from the elution cell.
28. The elution arrangement according to claim 27, wherein the adaptor further is configured to be used for forwarding the magnetic beads for reuse in the magnetic separator by pushing the adaptor towards an outlet of the elution cell and removing a retaining arrangement configured for keeping the magnetic beads inside the elution cell.
29. The elution arrangement according to claim 20, wherein the elution cell further comprises an adaptor which is positioned at a start positon in the elution cell when a slurry of magnetic beads starts to fill the elution cell from a bottom inlet of the elution cell, said start position being closer to the bottom inlet than an end position, which end position corresponds to the position of the adaptor when the filling of magnetic beads into the elution cell is completed, said adaptor keeping a force towards the flow direction of the slurry and allowing buffer to escape though the adaptor during the filling.
Type: Application
Filed: May 15, 2023
Publication Date: Oct 19, 2023
Inventors: Ola Lind (Uppsala), Johan Fredrik Avallin (Uppsala), Andreas Torbjorn Lundin (Uppsala), Nils Norrman (Uppsala), Ronnie Palmgren (Uppsala), Gustav Jose Rodrigo (Uppsala)
Application Number: 18/317,411