Centrifuge and method for cleaning a centrifuge

Abstract

The invention relates to a centrifuge for cleaning a reaction vessel unit and a method for cleaning such a centrifuge. The centrifuge has a rotor and a rotor chamber in which the rotor is arranged and rotatably mounted, the rotor having a receiving area for receiving the reaction vessel unit. The rotor chamber is bounded by a housing, the housing having a drain for removing liquid discharged from the reaction vessels and an inlet for filling the rotor chamber with a cleaning solution such that, when the rotor rotates, it is at least partially immersed in the cleaning solution and the solution is distributed within the rotor chamber, and / or the inlet is designed such that the cleaning solution is distributed within the rotor chamber when fed in by the rotating rotor.

Description

[0001] The present invention relates to a centrifuge for cleaning a reaction vessel unit with a rotor and a rotor chamber in which the rotor is arranged and rotatably mounted, wherein the rotor has a receiving area for receiving the reaction vessel unit.

[0002] EP 937502 A2 describes a method for handling a microtiter plate, wherein the microtiter plate is cleaned by centrifugation. For this purpose, the microtiter plate is placed in the rotating housing via a conveyor belt, so that the openings of the microtiter plate are directed away from the axis of rotation.

[0003] WO 2015 / 018878 A1 describes another centrifuge featuring an elastic arm that draws microtiter plates into and out of the centrifuge's rotor. The rotor is positioned very close to the surrounding housing and the drain channel located at the bottom. This short distance is intended to allow the resulting circulation wind to force the liquid effluent from the reaction vessels into the drain channel, where it can then be pumped out. Due to this small distance, there is a risk that the liquid level will rise above the drain channel. This could cause the rotor to become submerged in the liquid as it rotates. This is particularly critical when the liquid is a washing solution containing detergents, as the rotor would then froth the liquid.This foam can quickly fill a large portion of the rotor's volume and escape through the door. Furthermore, the described pump cannot effectively remove the foaming material; instead, it remains in the rotor chamber or the drainage channel. The rotor's close proximity to the drainage channel is primarily due to the cylindrical shape of the rotor chamber, which is designed to generate the desired circulating airflow.

[0004] It is known that in cylindrical rotor chambers of centrifuges, circulation winds are generated by the rotating rotor. In this context, reference is made to US 2007 / 0037684 A1, DE 103 55 179 A1, DBP 1033446, EP 2 705 903 A1 and DE 2404036.

[0005] WO 2018 / 234420 A1 discloses another centrifuge for cleaning reaction vessel units. This centrifuge has a rotor and a rotor chamber in which the rotor is rotatably mounted. A reaction vessel unit is inserted into the centrifuge with its openings facing outwards, so that when the rotor rotates, the reagents contained within are expelled from the respective reaction vessels. This allows the reaction vessels to be cleaned essentially without residue. This centrifuge can have a dispensing unit, wherein the dispensing unit has several dispensing nozzles. The dispensing nozzles are preferably arranged side by side along a line, with this line extending transversely to the direction of movement of the reaction vessel unit during loading or unloading of the centrifuge. The nozzles of the dispensing unit are arranged adjacent to an opening for loading and unloading the centrifuge with the reaction vessel unit.

[0006] WO2017 / 125598 A1 reveals another centrifuge, which in turn has a loading and unloading device in which reaction vessel units are positioned by means of a rigid sliding rod.

[0007] CN 102175855 A discloses a fully automatic 360° record washing machine. The rotational axis of this machine runs parallel to the horizontal plane, thus allowing the washing of several records simultaneously in one housing, thereby increasing efficiency and significantly reducing costs.

[0008] US 4,953,575 relates to a washing device for cuvettes. For this device, the cuvettes are placed in a holder within a rotor. Rotating the rotor removes the liquid from the cuvettes. The disclosed centrifuge housing has an opening at its lowest point through which the removed liquid can exit the housing.

[0009] JP 2009264927 A discloses a device comprising a drum in which a microplate can be placed. The drum can be loaded with several microtiter plates, which then rotate about a horizontal axis of rotation. The drum is loaded with the microtiter plate in such a way that its openings are directed towards the interior of the drum.

[0010] JP 2007 / 178355 A discloses a system for cleaning printed circuit boards in which one or more microtiter plates are placed in a rotating unit whose axis of rotation is vertical. The device has several nozzles that can spray the microtiter plates with a cleaning fluid from the outside.

[0011] From JP S51 439 67 U a centrifuge with a vertical axis of rotation is disclosed, in which it is revealed that the rotor can be cleaned by filling water into the chamber and rotating the rotor.

[0012] CN 113 000 230 A also discloses a centrifuge with a vertical axis of rotation for the automatic cleaning of disinfectants.

[0013] The invention is based on the objective of creating a centrifuge for cleaning a reaction vessel unit, which has a rotor and a rotor chamber in which the rotor is rotatably mounted, whereby contamination should be avoided with the centrifuge and reliable operation should be possible in the long term.

[0014] The problem is solved by the subject matter according to the independent patent claim.

[0015] Advantageous embodiments of the invention are specified in the respective dependent claims. A centrifuge according to the invention for cleaning a reaction vessel unit comprises a rotor and a rotor chamber in which the rotor is arranged and mounted, the rotor having a receiving area for receiving the reaction vessel unit. The rotor chamber is bounded by a housing, the housing having a drain for removing liquid discharged from the reaction vessels and an inlet for filling the rotor chamber with a cleaning solution such that the cleaning solution is distributed within the rotor chamber by contact with the rotor when the rotor is rotated without the reaction vessel units present, thus cleaning the rotor chamber. The axis of rotation of the rotor runs parallel to a base. A cleaning solution can therefore be supplied to this centrifuge and distributed within the rotor chamber.The rotor is used to distribute the cleaning solution. This will be discussed in more detail below in the explanation of the procedure for cleaning the centrifuge.

[0016] As the rotor rotates, it can at least partially immerse itself in the cleaning solution, distributing it within the rotor chamber, and / or the inlet is designed such that the cleaning solution is distributed within the rotor chamber as it is fed in by the rotating rotor. In this process, the cleaning solution can come into contact with the rotor and be distributed by the centrifugal forces acting on the rotor, and / or be carried along and distributed by the airflow generated by the rotor.

[0017] Because the rotor's axis of rotation runs parallel to a base, a partially filled rotor chamber distributes the cleaning solution throughout the entire chamber when the rotor is partially immersed in it. It is not necessary to completely fill the entire rotor chamber with the cleaning solution. Therefore, the rotor chamber does not need to be perfectly sealed. Furthermore, unlike an arrangement where the rotor's axis of rotation is perpendicular to a base, the cleaning solution is not simply distributed radially outwards by centrifugal force without being distributed throughout the entire rotor chamber.

[0018] Due to the parallel alignment of the rotation axis and the immersion, the cleaning solution in the rotor chamber is carried upwards by the rotor and evenly distributed in the rotor chamber by the resulting airflow.

[0019] When cleaning a reaction vessel unit in a centrifuge, where the contents of the reaction vessels are ejected, there is a risk that residues of the contents will remain in the rotor chamber and potentially be transferred to another reaction vessel unit. This is particularly critical when chemical or biological samples are contained in the reaction vessel units. In the case of biological samples, a single molecule, such as a segment of a DNA strand, transferred to another reaction vessel unit can represent an unacceptable level of contamination.

[0020] Centrifuges for cleaning reaction vessel units are now used with great success. However, they require regular cleaning. The inventive design of the centrifuge allows for self-cleaning or automatic cleaning. This enables the centrifuge to be part of an automated process and to be subjected to cleaning from time to time without requiring manual intervention from an operator. For example, the centrifuge can be cleaned multiple times during a multi-hour workflow without any manual intervention. This is a significant advantage over conventional centrifuges for cleaning reaction vessel units.

[0021] The outlet of the housing can also serve as the inlet. For example, an opening in the housing, forming either the outlet or the inlet, can be connected to a fluid line that has a branch, so that the fluid line splits into an inlet line and a drain line. The drain line is designed to discharge fluid, and the inlet line is designed to supply fluid. The drain line has a shut-off element to block the flow. When the drain line is blocked by the shut-off element, the fluid or cleaning solution can be supplied via the inlet line without flowing out through the outlet line and is directed exclusively to the rotor chamber.

[0022] The locking element can be a valve or, preferably, an automatically actuated hose clamp, provided that at least part of the drain line is designed as a hose. The hose clamp can be equipped with an actuator for automatic actuation. The actuator can be designed as an eccentric or as an electric or pneumatic piston mechanism.

[0023] The feed line can also be fluidically coupled to a dispensing unit integrated into the centrifuge, so that a cleaning solution can be supplied to the feed line via the dispensing unit. In such an embodiment of the centrifuge, the dispensing unit has the function of both dispensing solutions into reaction vessels of the reaction vessel units and supplying the cleaning solution to the rotor chamber.

[0024] The drain can be equipped with a suction pump and a siphon, the siphon being designed such that, when the suction pump is not activated, a liquid level below a predetermined level remains in the rotor chamber. This ensures that any cleaning solution present in the rotor chamber remains there, provided the cleaning solution level does not exceed the predetermined level. This predetermined level is preferably chosen such that, when rotating, the rotor immerses itself in the liquid and at least partially carries it along. The siphon thus acts as a sealing element, blocking the drain line up to a certain level when the suction pump is not activated.

[0025] A level sensor can be provided in the rotor chamber to detect the fill level. This level sensor can be an ultrasonic sensor that scans the surface of the liquid. In this case, it is advantageous to position the rotor so that it does not obstruct the measurement. Alternatively, the fill level can be determined by one or more temperature sensors mounted on the inner surface of the housing, each measuring a specific liquid level.

[0026] The inlet can be positioned above the rotor's axis of rotation, allowing the cleaning solution to come into contact with the rotor when it is supplied. The rotor can, of course, be in a position where it does not come into contact with the cleaning solution supplied via the inlet, for example, if it is vertically oriented. In this case, the cleaning fluid supplied in this way is carried along by a rotating, especially high-speed, rotor and distributed within the rotor chamber. Even low rotational speeds of a few rpm are sufficient for this. Typically, the rotor is rotated at speeds of at least 10 rpm or at least 50 rpm or more. The rotor should not be rotated faster than 100 rpm once the cleaning solution has been introduced into the rotor chamber to a predetermined level, allowing the rotor to be immersed in the cleaning solution. However, if the cleaning solution is introduced into the rotor chamber, for example...If the cleaning solution is introduced by atomization without accumulating at the bottom of the rotor chamber, then the rotor can also be operated at higher speeds, for example at least 100 rpm. Speeds of at least 500 rpm or at least 1000 rpm may also be advantageous.

[0027] The inlet can also have one or more nozzles to atomize the cleaning solution into the rotor chamber. Cleaning fluid atomized in this way within the rotor chamber can then be evenly distributed by rotating the rotor.

[0028] Another aspect concerns a method for cleaning a centrifuge for cleaning a reaction vessel unit, wherein the centrifuge has a rotor and a rotor chamber in which the rotor is arranged and rotatably mounted, wherein the rotor has a receiving area for receiving the reaction vessel unit, and wherein the axis of rotation of the rotor is parallel to a base surface. The following steps are carried out in this method: The rotor chamber is filled with a cleaning fluid either at least to a predetermined level, so that when the rotor rotates it is at least partially immersed in the cleaning solution, and / or the cleaning solution is supplied to the rotor chamber in such a way that it can either come into contact with the rotor and / or is introduced into an area of ​​the rotor chamber where it is carried along by an airflow when the rotor rotates, the rotor is rotated / moved, thereby distributing the cleaning solution in the rotor chamber, and the cleaning solution is removed from the rotor chamber.

[0029] Removing the cleaning solution carries away the contaminants in the rotor chamber. The cleaning solution can then flow out through the drain and thus be removed from the rotor chamber. This can be controlled, for example, by opening a shut-off valve in a drain line.

[0030] The rotor in such a centrifuge has two functions. Firstly, it empties the reaction vessel units by spinning the rotor to eject the contents. Secondly, it distributes the cleaning solution within the rotor chamber, ensuring uniform and reliable cleaning. This distribution can occur in two ways: either the rotor partially immerses itself in the solution as it rotates, carrying it along, or it is directly carried by the rotor or by the airflow it generates, distributing the cleaning solution within the rotor chamber. This is particularly true when the cleaning solution is atomized within the rotor chamber; in this case, rotating the rotor creates a mist of the cleaning solution that is evenly distributed throughout the chamber.

[0031] The cleaning solution can be a non-foaming solution containing, for example, formaldehyde or paraformaldehyde. Such a non-foaming cleaning solution can drain from the rotor chamber on its own, without any further action required. Rotating the rotor can serve to drive the cleaning solution to the drain and remove it from the rotor chamber. However, the cleaning solution can also drain automatically when the rotor is stationary, provided the drain line is properly unblocked.

[0032] The cleaning solution can also be a foaming cleaning solution, particularly one containing surfactants. As the cleaning solution is distributed by the rotor, it foams up in the rotor chamber. To remove the foamed cleaning solution, an anti-foaming solution, such as one containing alcohol, can be added to the rotor chamber. This causes the foam to collapse and flow out through the drain. The drainage and removal of the cleaning solution from the rotor chamber can also be aided by rotating the rotor, just as with a non-foaming cleaning solution.

[0033] The foam-reducing solution can also be distributed in the rotor chamber during or after feeding by rotating the rotor, in order to effectively distribute the foam-reducing solution in the rotor chamber.

[0034] This procedure can be performed using a centrifuge as described above.

[0035] The invention is explained in more detail below by way of example with reference to the drawings. The drawings show: Figure 1 a part of a centrifuge housing in perspective view, Figure 2 the part of the housing made of Figure 1 in a sectional view from a slightly oblique front view, Figure 3 the part of the housing made of Figure 1 in a longitudinal section Figure 4a the centrifuge according to a first embodiment with the housing part made of Figure 1 in a longitudinal section, and Figure 4b the centrifuge according to a second embodiment with the housing part made of Figure 1 in a longitudinal section.

[0036] A centrifuge according to the invention 1 ( Figure 4a ) has a rotor 2, a housing 3, a drive device 4 for rotating the rotor 2 about a rotation axis 5.

[0037] The rotor has at least one receiving area 6 for receiving a reaction vessel unit 7. The reaction vessel unit 7 is typically a microtiter plate. Such microtiter plates can be configured with a varying number of reaction vessels. Microtiter plates with six to 4096 reaction vessels are common, with 96, 384, or 1536 reaction vessels being the most frequent versions. In microtiter plates with 384 or 1536 reaction vessels, the individual reaction vessels are so thin that a liquid normally adheres to them solely due to capillary action, so that even when such a microtiter plate is positioned with its openings facing downwards, the liquid does not leak out. This is not the case for microtiter plates with fewer reaction vessels, which are each larger. Such a reaction vessel unit 7 can be inserted into a receiving area 6 on its own or mounted on a support unit.Preferably, a carrier unit is used which has a coupling element that can be coupled to a loading and unloading device 8. Such a loading and unloading device is described, for example, in DE 10 2016 101 163. It is explained in more detail below.

[0038] The housing 3 defines a rotor chamber 9. In the present embodiment, the area of ​​the housing 3 defining the rotor chamber 9 is formed from a lower shell 10, an upper shell 11, a front end wall 12, and a rear end wall 13. Further parts of the housing adjoin the rear end wall, which are not shown in the accompanying figures.

[0039] In the front end wall 12 and the rear end wall 13, there is a ball bearing 14 in each, in which a continuous shaft 15 of the rotor 2 is rotatably mounted. The center line of the shaft 15 forms the axis of rotation 5. The axis of rotation 5 runs parallel to a base surface 16, which is formed by the underside of the lower shell 10.

[0040] The rear end of the shaft 15 is coupled to the drive unit 4. The further part of the housing, which connects to the rear of the housing, contains the drive unit 17, the loading and unloading unit 8, and a central control unit (not shown) with which all components of the centrifuge 1 are controlled.

[0041] A balcony 18 is attached to the outside of the front end wall 12, which serves to accommodate a reaction vessel unit 7. At the level of the balcony 18, a loading and unloading opening 19 is formed in the front end wall 12, through which a reaction vessel unit 7 can be inserted into and removed from the rotor chamber 9. The loading and unloading opening 19 is equipped with a pivoting door 20, so that the rotor chamber can be closed.

[0042] Adjacent to this door 20, a dispensing unit 39 with several dispensing nozzles 40 and / or an optical detection unit, in particular in the form of a line camera, may be provided.

[0043] The loading and unloading device 8 has a sliding rod (not shown) which can be moved horizontally through the rotor chamber 9 via a through-opening 21 in the rear end wall 13. The loading and unloading device 8 has a linear drive for this purpose, enabling the sliding rod to be moved linearly along its longitudinal direction. The sliding rod has a coupling element at its free end, which can be coupled to a corresponding coupling element on the carrier unit or on a reaction vessel unit 7, so that the carrier unit with a reaction vessel unit, or the reaction vessel unit directly, can be moved from the balcony 18 through the loading and unloading opening 19 into the rotor chamber 9 by moving the sliding rod. The rotor 2 is arranged with a receiving area 6 adjacent to the loading and unloading opening 19, so that the carrier unit or reaction vessel unit can be moved into the rotor chamber 9.The reaction vessel unit is moved into the receiving area 6 of the rotor 2. The coupling between the sliding rod and the carrier unit or the reaction vessel unit 7 can be released, so that the carrier unit or the reaction vessel unit is freely movable in the rotor 2 and the rotor can be rotated accordingly with this unit.

[0044] By means of the sliding rod of the loading and unloading device 8, the carrier unit or reaction vessel unit 7 can be pushed from the receiving area 6 of the rotor 2 back onto the balcony 18 through the loading and unloading opening 19. The reaction vessel unit 7 can then be removed from the balcony 18, for example, by means of a robot.

[0045] The lower shell 10 has a groove 22 which runs approximately parallel to the axis of rotation 5. The groove 22 extends from the rear end wall 13 to the area of ​​the front end wall 12, being inclined or sloping forwards ( Figure 4a An outlet opening 23 is formed on the front of the lower bowl 10, into which the channel 22 opens. A connection pin 24 is arranged at the outlet opening 23, to which a hose 25 can be connected. The hose 25 typically opens into a receiving container (not shown) that collects the liquids which are ejected from the reaction vessels of the reaction vessel unit 7 in the centrifuge 1. The container preferably has a vent opening, or the hose extends through the container with some clearance so that liquid flowing from the centrifuge through the hose 25 does not create back pressure in the container.

[0046] The lower bowl 10 has inner surfaces adjacent to the channel 22, which extend obliquely upwards from an upper edge of the channel 22 ( Fig. 2 These inner surfaces thus form a funnel 26 and are hereinafter referred to as funnel surfaces 27. The funnel surfaces 27 are inclined at an angle of approximately 30° to 60° to the horizontal. Essentially flat means that the funnel surfaces have a radius of curvature of more than 0.5 m and preferably more than 1 m. In the present embodiment, the funnel surfaces 27 extend laterally beyond the area of ​​the rotor 2, even when it is in its horizontal position.

[0047] From the outer edge of the funnel 26 or the funnel surfaces 27, the inner surfaces of the lower bowl 10 extend approximately vertically upwards. They thus form vertical surfaces 28.

[0048] The upper shell 11 is attached to the upper edge of the lower shell 10. The upper shell 11 has a trough-like shape with a semicircular cross-section. The inner surface of the upper shell 11 is flush with the vertical surface 28. The cross-section of the housing 3 is therefore not cylindrical, but exhibits a cylindrical curvature only in the upper region of the shell 11, whereas the lower shell 10 tapers in cross-section and terminates in the trough 22. The trough 22 is slightly offset downwards from the funnel-shaped lower shell 10 and has two approximately vertically arranged side walls 37a, 37b. The trough itself is inclined to allow any liquid contained within it to drain away.

[0049] In the present embodiment, the lower shell 10 and the upper shell 11 are made of metal. The inner surfaces of the lower shell 10 and the upper shell 11 are coated with a smooth plastic layer, so that liquids ejected from the reaction vessels of the reaction vessel units 7 run quickly along the inner surfaces, are guided from the hopper 26 to the channel 22, and exit the rotor chamber 9 there. The plastic layer is made of PTFE.

[0050] The upper edge of the channel 22 is spaced from the axis of rotation 5 by at least 1.32 times the maximum radius of the rotor 2. This creates a free space in the funnel 26 that is not touched by the rotor 2 during one revolution. Liquid can accumulate in this free space. Figure 2A maximum level 29 of the liquid is shown, which can accumulate in the funnel 26 without coming into contact with the rotor. This makes it possible, in the case of large-volume reaction vessels of a reaction vessel unit 7, to empty the main part of the liquid in one go, collect it in the funnel 26, and allow it to gradually flow out through the outlet opening 23.

[0051] Furthermore, due to the large distance between the trough 22 and the rotor, and the resulting large cross-section, the airflow generated by the rotating rotor is minimal in this area. This allows liquid to settle at the bottom of the funnel, i.e., in the trough 22, and flow out of the trough 22 through the outlet opening 23. Due to the low flow velocity, there is also little risk of liquids located in the funnel-shaped area adjacent to the trough 22 being forced upwards by the airflow.

[0052] Since the channel is bounded by approximately vertical side walls 37a, 37b, even if an airflow is generated in the direction of rotation 38, this cannot drive the liquid out of the channel. Once a liquid is in the channel 22, it is therefore trapped and can only escape through the outlet opening 23. In the case of the Figure 2 In the illustrated embodiment, an airflow can strike the side wall 37a, which is located downstream in the channel 22 in the direction of rotation 38 of the rotor. However, since the side wall 37a is approximately perpendicular to the direction of flow, the liquid in the channel can no longer be driven back into the rotor chamber. In principle, a channel with an approximately vertical side wall on the side of the channel 22 downstream in the direction of rotation 38 is sufficient. However, from a manufacturing perspective, it is advantageous to produce a channel with two approximately vertical side walls 37a and 37b.

[0053] This design of the funnel 26 and the channel 22 eliminates the need for a suction pump.

[0054] The dispensing unit 30, which can also be referred to as the dispensing head, has several dispensing nozzles 31 arranged along a straight line with their openings pointing downwards. The dispensing unit 30 is connected to a reagent line 32, through which reagents are supplied to the dispensing unit 30 and then dispensed downwards through the individual dispensing nozzles 31. The dispensing unit essentially performs the function known from WO 2018 / 234420 A1, namely that reaction vessels of a reaction vessel unit 7 can be filled with reagents when the reaction vessel unit 7 is moved past the dispensing unit 30 by means of the loading and unloading device 8.

[0055] In the first embodiment of the present invention ( Figure 4aThe balcony 18 in the area below the dispensing unit 30 is designed with an upwardly open channel 33 in which the reagents dispensed by the dispensing nozzles 31 are collected if no reaction vessel unit 7 is arranged below the dispensing nozzles 31, as shown in Figure 4aThe channel 33 is connected to a collecting hose 34, allowing the reagents collected in the channel 33 to flow away via the collecting hose 34. The collecting hose 34 opens into the hose 25 at a branch 35. With respect to the rotor chamber 9, the collecting hose forms an inlet line and the hose 25 a drain line for removing liquids from the rotor chamber 9, starting from the branch 35. A shut-off element 36 is arranged in the hose 25 downstream of the branch 35, which can be used to close the passage through the hose 25. The shut-off element 36 can be a preferably electrically actuated valve to open or close the passage through the hose. The shut-off element can also be a hose clamp, which can be opened or closed, for example, by an actuator or by means of an eccentric mechanism.

[0056] If the blocking element 36 blocks the passage of the hose 25 and a cleaning solution is supplied via the dispensing unit 30 through the collecting hose 34, the cleaning solution flows through the hose 25 and the outlet opening 23 into the rotor chamber 9. The outlet opening 23 then serves as the inlet for the cleaning solution. In principle, it would be possible to supply cleaning solution to the rotor chamber 9 up to the level of the top of the balcony 18. However, it is advisable not to flood the ball bearings 14 of the shaft 15 with cleaning solution. The rotor chamber 9 is filled to above the level 29 ( Figure 2 ) filled with cleaning solution, so that when rotor 2 rotates, it immerses itself in the cleaning solution, carrying some of the cleaning solution with it and distributing it within rotor chamber 9. In practice, it has been shown that rotor chamber 9 is filled at least to a level of 43, as expected. Figure 2The level 43 lies approximately 5% of the radius of the rotor 2 and preferably at least 10% of the radius of the rotor 2 above the level 29, which is just not touched when the rotor 2 rotates.

[0057] By rotating the rotor 2, the cleaning solution is distributed in the rotor chamber 9, so that all parts of the rotor chamber 9 come into contact with the cleaning solution.

[0058] While the cleaning solution is being distributed by rotating the rotor 2, more cleaning solution can continue to be fed in via the dispensing unit 30 to slow down or prevent the level of the cleaning solution from dropping.

[0059] Once the cleaning solution is sufficiently distributed in rotor chamber 9, a predetermined time period can be allowed to elapse so that the cleaning solution can absorb the contaminants. During this time, the rotation of the rotor can be adjusted or the rotor can be continued to create a continuous turbulence of the cleaning solution within the rotor chamber through the airflow.

[0060] Once this cleaning step is complete, the locking element 36 is opened, allowing the cleaning solution to drain through the outlet opening 23. This can be assisted by further rotation of the rotor, so that the cleaning solution is forced into the channel 22.

[0061] This cleaning process of the rotor chamber 9 can be carried out fully automatically and is controlled by the central control unit.

[0062] A non-foaming cleaning solution, such as formaldehyde or paraformaldehyde, is preferably used as the cleaning solution, with which the entire rotor chamber 9 can be reliably disinfected.

[0063] For biological samples, especially those containing bacteria, it is advantageous if the cleaning solution contains surfactants that cause the cleaning solution to foam when the rotor is turned. Foaming of the cleaning solution results in a very rapid and uniform distribution of the cleaning solution within the rotor chamber 9. Therefore, the rotational speed and / or duration of the rotor's rotation within the rotor chamber 9 can be, and should be, significantly reduced compared to distributing a non-foaming cleaning solution. To completely remove the foamed cleaning solution from the rotor chamber 9, an antifoaming solution is supplied to the rotor chamber 9 via the dispensing unit 30 and the collection tube 34 and distributed by rotating the rotor 2. This causes the foam in the rotor chamber 9 to collapse, and the cleaning solution flows out of the rotor chamber 9 along with the antifoaming solution.Such a foam-reducing solution can, for example, contain alcohol. An alcohol-based solution also has the advantage of evaporating very quickly, thus allowing the rotor chamber 9 to dry correspondingly rapidly.

[0064] A second embodiment of centrifuge 1 ( Figure 4bThe second embodiment is essentially identical to the first embodiment, unless otherwise explained below. Therefore, identical parts are designated with the same reference numerals and will not be explained again. The second embodiment does not need to include a dispensing unit. A feed opening 39 is formed on the rear end wall 13 in the area above the shaft 15. This feed opening is connected to the reagent line 32 and opens into the rotor chamber 9. In the present embodiment, an atomizing nozzle 40 is arranged in the feed opening 39. Reagents supplied via the reagent line 32 are atomized into the rotor chamber 9 by this nozzle. By supplying a cleaning solution through the feed opening 39, it is introduced into the rotor chamber 9 and atomized into a mist by the atomizing nozzle 40. Rotating the rotor 2 distributes this mist evenly within the rotor chamber 9.Part of the cleaning solution settles in the channel 22 and flows out of the rotor chamber 9 via the outlet opening 23 and the hose 25. This allows the cleaning solution to be continuously circulated and removed from the rotor chamber 9 to eliminate contaminants. Optionally, a blocking element 36 can be provided in the hose 25 to close off the passage of the hose 25 and retain the cleaning solution in the rotor chamber 9.

[0065] It may also be useful to rotate the rotor alternately in different directions during the cleaning process in order to achieve the most even distribution of the cleaning solution in the rotor chamber.

[0066] In principle, it is also possible not to arrange an atomizing nozzle 40 in the feed opening 39. This depends on the dimensions of the rotor chamber, the rotor itself, and the airflow generated during rotor rotation. Sufficient distribution of the cleaning solution can be achieved solely through the rotation of the rotor and the resulting airflow, without the need for atomizing nozzles. On the other hand, it may also be advantageous to provide several feed openings 39, particularly on the upper shell 11, to achieve uniform distribution across the entire width of the rotor chamber 9 in the direction of the axis of rotation 5.

[0067] A pressure nozzle can also be inserted into the feed opening(s) 39. A pressure nozzle is a nozzle that opens when the cleaning solution is fed into the nozzle at a predetermined pressure. This allows the timing of the supply of cleaning solution to the rotor chamber to be precisely controlled. The pressure nozzle can also function as an atomizing nozzle.

[0068] Furthermore, in the second embodiment, if the locking element 36 is provided in the hose 25, enough cleaning solution can be introduced into the rotor chamber 9 via the feed opening 39 until a fill level corresponding to level 43 is reached. Figure 2 This is achieved. Then, by rotating the rotor, as explained above using the first embodiment, the cleaning solution can be evenly distributed in the rotor chamber 9.

[0069] Furthermore, the second embodiment can be modified such that the hose 25 is shaped into a siphon 41 ( Figure 4b), i.e., that the hose 25 is guided upwards a short distance from the outlet opening 23 and then deflected downwards, so that liquid flowing into the hose 25 only overcomes the siphon when the liquid level in the rotor chamber 9 has reached the height of the siphon. With such an arrangement of the hose 25, either a suction pump 42 must be provided in the hose 25 to completely extract the liquid from the rotor chamber 9 over the siphon 41 when necessary, or a lifting mechanism can be provided that lowers the hose 25 in such a way that the siphon 41 is lifted and the liquid contained in the hose 25 flows out by gravity alone.

[0070] In the second embodiment, both non-foaming and foaming cleaning solutions can be used. If foaming cleaning solutions are used, it is advantageous, as in the first embodiment, to introduce a foam-reducing solution into the rotor chamber 9 to remove the foaming cleaning solution from the rotor chamber 9.

[0071] The above embodiments and variations demonstrate that the cleaning solution(s) can be supplied to and discharged from the rotor chamber 9 in different ways to clean it. All embodiments and variations share the common feature that the rotor 2, which is inherently present in the centrifuge 1, is used to distribute the cleaning solution evenly within the rotor chamber 9. The rotational speed and duration of rotation of the rotor 2 must be adjusted according to the geometry of the rotor chamber 9 and the behavior of the cleaning solution. In this context, it can be particularly advantageous (regardless of the centrifuge's design) to rotate the rotor 2 at least once clockwise and at least once counterclockwise to achieve the most uniform distribution of the cleaning solution within the rotor chamber 9.If one or more atomizing nozzles 40 are used, it is advisable to supply the cleaning solution under pressure so that the atomizing nozzles 40 ensure efficient atomization of the cleaning solution.

[0072] The supply, uniform distribution, and removal of the cleaning solution from the rotor chamber 9 can be performed fully automatically. This allows the centrifuge 1 to be integrated into an automated production process in which numerous reaction vessel units 7 are repeatedly cleaned, ensuring that no contamination occurs from one reaction vessel unit 7 to another. The intervals for cleaning the rotor chamber 9 must be adjusted according to the quantity and reactivity of the reagents contained in the reaction vessel units 7. For example, such a cleaning process can be performed at intervals of no more than 10 minutes or no more than 60 minutes. However, with less reactive reagents and small quantities, it may also be advantageous to perform such a cleaning process only once a day.

[0073] The cleaning process allows for complete disinfection of the interior and reliably prevents contamination by viruses, bacteria or other infectious agents.

[0074] Furthermore, agents that destroy nucleic acids and thus prevent contamination can be used as solvents in DNA-containing samples. These agents include, for example, perchlorate, strong oxidizing agents, and / or enzymes such as DNases.

[0075] If an unforeseen contamination of the rotor chamber 9 occurs, such as through the bursting of a reaction vessel unit 7 during centrifugation, the system can be completely cleaned without having to open the interior or the device. Reference symbol list

[0076] 1 Centrifuge 2 Rotor 3 Housing 4 Drive unit 5 Rotation axis 6 Loading area 7 Reaction vessel unit 8 Loading and unloading device 9 Rotor chamber 10 Lower tray 10a Lower tray 11 Upper tray 11a Upper tray 12 Front end wall 12a Front end wall 13 Rear end wall 13a Rear end wall 14 Ball bearing 15 Shaft 16 Base 17 Rotor chamber 18 Balcony 19 Vent 20 Door 21 Through opening 22 Trough 23 Outlet opening 24 Connection pin 25 Hose 26 Funnel 27 Funnel surface 28 Vertical surface 29 Level 30 Dispensing unit 31 Dispensing nozzle 32 Reagent line 33 Trough 34 Collecting hose 35 Branch 36 Locking element 37a Side wall 37b Side wall 38 Direction of rotation 39 Feed opening 40 Atomizing nozzle 41 Siphon 42 Suction pump 43 Level

Claims

1. A centrifuge (1) for cleaning a reaction vessel unit (7), comprising a rotor (2) and a rotor space (9) in which the rotor (2) is arranged and rotatably mounted, the rotor (2) comprising a receiving area (6) for receiving the reaction vessel unit (7), and the rotor space (9) being delimited by a housing (3), the housing (3) comprising an outlet for discharging liquid discharged from the reaction vessels and being provided with an inlet for supplying a cleaning solution to the rotor chamber (9) in such a way that the cleaning solution is spread by rotating the rotor (2) without the reaction vessel units (7) in the rotor chamber (9) through contact with the rotor (2), so that the rotor chamber (9) is cleaned, the axis of rotation (5) of the rotor (2) extending parallel to a base surface (16) and the centrifuge comprising a control device, characterized in that the control device is designed such that - the rotor chamber (9) is filled with a cleaning solution at least up to a level (43) so that, when the rotor (2) is rotated, it is at least partially immersed in the cleaning solution, and the following steps are performed: - rotating the rotor (2), causing the cleaning solution to be spread in the rotor space (9), and - removing the cleaning solution from the rotor space (9).

2. The centrifuge (1) according to claim 1, characterized in that the outlet of the housing (3) also forms the inlet.

3. The centrifuge (1) according to claim 2, characterized in that an opening in the housing (3), which forms the outlet and the inlet, is connected to a fluid line which comprises a branch and branches into an inlet line and an outlet line, the outlet line being designed to discharge a fluid and the inlet line being designed to supply a fluid, and the outlet line comprising a blocking element (36) for blocking the outlet line.

4. The centrifuge (1) according to claim 3, characterized in that the inlet line is fluidically coupled to a dispensing device integrated in the centrifuge (1), so that a cleaning solution can be supplied to the inlet line by means of the dispensing device.

5. The centrifuge (1) according to any one of claims 1 to 4, characterized in that the outlet comprises a suction pump and a siphon (41), the siphon (41) being designed such that, when the suction pump is not actuated, a liquid with a filling level below a predetermined filling level remains in the rotor space (9).

6. The centrifuge (1) according to any one of claims 1 to 5, characterized in that a filling level sensor is provided for detecting the filling level in the rotor space (9).

7. The centrifuge (1) according to any one of claims 1 to 6, characterized in that the inlet is arranged above an axis of rotation of the rotor (2), so that the cleaning solution can come into contact with the rotor (2) if it is supplied.

8. The centrifuge (1) according to any one of claims 1 to 7, characterized in that the inlet comprises one or more nozzles to atomize the cleaning solution into the rotor space (9).

9. The centrifuge (1) according to any one of claims 1 to 8, characterized in that the rotor space (9) is filled with the cleaning solution up to a predetermined level, and the rotor (2) is designed such that it is at least partially immersed in the cleaning solution during its rotation and spreads it in the rotor space (9).

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