CH704398A1 - Device for storing and handling petri dishes, comprises storage device for supporting petri dishes with lid, inspection device for automated inspection of petri dishes without lid, and transfer device for transferring petri dishes - Google Patents

Abstract

The device comprises a storage device for supporting petri dishes with a lid, an inspection device (2) for automated inspection of the petri dishes without the lid, and a transfer device (3) for transferring the petri dishes between the storage device and the inspection device. The transfer device comprises a gripper, with which each petri dish is laterally gripped without the lid at a bottom wall. The petri dishes comprise a bottom and the lid, where a bottom wall is arranged at a circumference of the bottom. The transfer device comprises a transfer station (4). The device comprises a storage device for supporting petri dishes with a lid, an inspection device (2) for automated inspection of the petri dishes without the lid, and a transfer device (3) for transferring the petri dishes between the storage device and the inspection device. The transfer device comprises a gripper, with which each petri dish is laterally gripped without the lid at a bottom wall. The petri dishes comprise a bottom and the lid, where a bottom wall is arranged at a circumference of the bottom. The transfer device comprises: a transfer station (4) for receiving the petri dish with a bottom lid, from which each petri dish is gripped without the lid by the gripper; a turning drive, with which the gripper is vertically reversible with a recorded bottom of the petri dish above the lid lying in the transfer station; and a horizontal drive, with which the gripper is backwardly movable from the transfer device for the inspection device. A turning drive is reversible at more than 90[deg] . The device further comprises: a lifting actuator, with which the gripper is vertically displaceable relative to the transfer station; two transfer stations, both of which are movable. A common lift drive is provided for the both transfer stations. The device is adapted to hold the lid during the inspection through the inspection device with the gripper. The storage device includes a storage place for the petri dishes with the bottom lid, and/or an envelope device to transport the petri dishes between the storage places and the transfer device. The envelope device is arranged for transferring the petri dishes between the storage places and the transfer station without turning the petri dish. The storage places are formed from storage shafts, where each storage shaft comprises the storage places one above the other. The storage shafts are arranged on a carrousel. The envelope device comprises two vertically movable carriages, which are arranged one above the other on a common lift column. The gripper comprises two mutually movable fingers, which comprise three elevations oppositely directed to an impact of the wall of the petri dishes. One of the fingers has a spring, which carries a base portion, where one of the elevations is arranged at the base portion. Two arc-shaped fixing elements are provided for the lid of the petri dish by which the lid is flexibly and temporarily controlled. The fixing elements are arranged at a transfer table of the transfer station. The transfer device for the transfer station comprises a common carrier plate for both transfer stations and the gripper, on which the transfer station or the transfer stations and the grippers are arranged, where a single-piece carrier plate is an L-shaped carrier plate. The transfer device in an area of the gripper comprises a temporarily controllable turn-off optical sensor, which is arranged and designed for detecting a presence and/or absence of the petri dish into the gripper. The sensor at each transfer station is provided for the presence and/or absence of the lid into the transfer station. The gripper is designed in such a way that the gripper of a basic position is present in a snatching state, where the fixing element is designed in such a way that the fixing element of the basic position is present in an opened non-fixing position. The gripper comprises two fingers, which are arranged respectively on a shaft that is movably controlled away from each other. Each finger is fixed in a horizontal plane pivotally mounted on the shaft, is independently fixed in a normal position centering to the shaft, and is fixed with its backside via a flat spring to the shaft. The fingers of the gripper are designed and arranged for a point-shaped contact by end portions of the fingers. The fingers of the gripper are formed from the base portion and an exchange part detachably attached to the base portion. The exchange part is configured to the point-shaped contact the exchange part is made of spring steel. The gripper is designed in such a way that a size of an angle from a center of a gripping portion is provided to be extreme for contacting the petri dish. A contact part of the fingers of the gripper is 90[deg] . The storage device on its wall comprises a second auxiliary door, on which the transfer device is located. The second auxiliary door is present below a first auxiliary door. A lifting device comprises the sensor by which the presence and/or absence of the petri dish is ascertainable. Independent claims are included for: (1) a storage device; and (2) a storage shaft.

Description

Field of the invention

The invention relates to a device for storage and handling of Petri dishes. Furthermore, the invention relates to a storage device and a storage shaft.

background

Petri dishes are flat, round, transparent bowls with overlapping lid, which are widely used in biology, medicine or chemistry. Petri dishes are used for the cultivation of microorganisms and cell cultures. A flat layer of gelatinous culture medium is filled into the Petri dish and supplies the growing microorganisms with water and the necessary nutrients.

Application specific microorganisms are introduced locally into the nutrient medium. Subsequently, the Petri dishes are usually incubated with the lid down and the culture medium upwards. In this storage, the wiped of the plate on the lid, which improves the closure between the lid and bowl. Excess water does not form on the nutrient medium, but preferably accumulates on the lid.

During the incubation period, the growth of the cultures is visually inspected several times. In applications where large numbers of plates are used, there is a need to automate the process. In this case, each time a Petri dish is removed from the incubator or the storage device and fed to an inspection device according to certain timing. For inspection, the inspection device should be fed with the plates with the nutrient medium down.

For transferring the petri dishes between storage device and inspection device, a transfer device is needed. Usually, this has a pivot arm, which is arranged on a wall of the incubation chamber or storage device. A Petri dish is detected by a vacuum suction device, which is arranged at the outer end of the pivot arm, and removed by means of a rotational movement of 180 degrees from the incubator and rotated simultaneously. For the inspection device, the vacuum suction device must be removed for inspection.

Further storage shafts are known for the storage of laboratory objects, which each provide space for several laboratory objects on top of each other.

Presentation of the invention

In a first aspect of the invention, the object to be solved to provide a device for storage and handling of Petri dishes, which allows efficient handling of the Petri dishes.

This object is achieved by the device according to claim 1. Accordingly, the transfer device has a gripper with which a respective Petri dish without the cover on the side walls of the bottom can be laterally gripped. The advantage of this solution is that the gripper acts on the petri dish in contrast to a vacuum suction essentially only laterally, but not centrally, so that the Petri dish remains easily accessible for inspection.

Preferably, the transfer device has a transfer station for receiving a Petri dish with the lid down. From this, a Petri dish without a lid is gripped by the gripper and lifted upwards, so that the lid remains on the transfer station.

It is advantageous in this case, when the transfer device has a turning drive, which is designed so that the gripper is turned with the recorded Petri dish vertically above the lid. It can be seen that this way the risk of contamination can be reduced by removing droplets which, when turning over the Petri dish, e.g. due to the draft, fall down in the lid and not be dumped uncontrollably elsewhere in the device.

In a further advantageous embodiment, the device has a lift drive, with which the gripper can be moved vertically above the transfer station and relative to this, i. can be moved in a vertical translation movement. For this purpose, either the gripper, or the transfer station, or both parts can be moved. Thanks to the vertical lifting, tilting of the soil of the Petri dish, which is picked up by the gripper, in its lid can be avoided.

In general, the storage device will form a plurality of storage spaces for Petri dishes, and the device will be designed so that the Petri dishes are stored in the storage areas with the lid down. In addition, in addition to the transfer device, a transfer device may be provided to transport the petri dishes between the storage bins and the transfer device back and forth. The handling device can be arranged at least partially in the storage device.

The storage bins for the Petri dishes are advantageously formed by several storage shafts. Each of these storage shafts has several storage bins on top of each other, so that the Petri dishes can be stored as in a tower. In a particularly advantageous embodiment, these storage shafts are arranged on a carousel, so that each of them can be brought to the handling device by turning the carousel.

In a second aspect, the invention relates to a storage device for receiving laboratory objects, in particular Petri dishes or microtiter plates. This bearing device may be particularly (but not only) suitable for use in the device described above. The storage device should allow easy assembly and disassembly of the storage shafts. According to the claim, the storage device has at least one storage shaft, each storage shaft having a plurality of storage bins for receiving a respective laboratory object on top of each other. At the bottom of each bearing shaft (14) at least one opening is arranged, in which engages at least one pin of a pad of the bearing shaft. From above, the storage shafts are held by a resilient tongue. By deformation of the tongue, a bearing shaft can be lifted, detached from the pins and removed from the bearing device.

In a third aspect, the invention relates to a storage shaft for receiving Petri dishes, which is particularly (but not only) suitable for use in the device described above and should allow compact storage. The storage shaft has a rear wall and two side walls. At least on the side walls, optionally also on the rear wall, pads for the peripheral recording of the Petri dishes are provided. The rear wall merges with two transitional areas in the two side walls. Each transition area is rounded, or it runs obliquely to the rear wall and the respective adjacent side wall. This embodiment, which takes into account the round design of Petri dishes, has the advantage that the storage shafts can be arranged closely in a circle, for example on a carousel, so that storage with high spatial capacity is possible.

Brief description of the drawings

Further embodiments, advantages and applications of the invention will become apparent from the dependent claims and from the following description with reference to the figures. Showing: <Tb> FIG. 1 <sep> a view of a plant from above, <Tb> FIG. 2 <sep> is a view of the transfer device and the adjacent components, <Tb> FIG. 3 <sep> part of the transfer device, <Tb> FIG. 4 <sep> an embodiment of a gripper, <Tb> FIG. 5 <sep> one of several conditions of the transfer station, <Tb> FIG. 6 <sep> a storage pit for Petri dishes, <Tb> FIG. 7 <sep> a detail (circle A) of the bearing shaft of FIG. 6, <Tb> FIG. 8 <sep> a fastening variant for the storage shafts, <Tb> FIG. 9 <sep> a transfer device with two transfer stations on top of each other and <Tb> FIG. 10 <sep> an alternative embodiment to the gripper of Fig. 4th

Ways to carry out the invention

Fig. 1 shows a device for storage and handling of Petri dishes from above. It comprises a storage device 1, an inspection device 2, a transfer device 3, a transfer station 4 and a transfer device 5. The structure and function of these components are described in detail below.

The storage device 1 is preferably as an incubator, i. designed as a climate chamber, in the interior by means of a suitable air conditioning, a desired temperature and atmosphere can be maintained. It has a wall 10 which encloses an interior 11. In the interior 11 concentric two independently rotatable carousels 12 and 13 are arranged, which each carry a circle of storage shafts 14, of which in Fig. 1, only a part is shown. Each storage shaft 14 forms a plurality of storage bins for Petri dishes 15 one above the other.

In a corner of the inner space 11, the handling device 5 is further arranged, which serves to transport the Petri dishes 15 between the storage bins and the transfer device 3 back and forth. For this purpose, the handling device has at least one carriage 16, which can be moved vertically on a lift column 16a, and on which a bucket 17, which can be moved horizontally and is pivotable about a vertical axis, is arranged. This blade can be retracted in the shown in Fig. 1 pivoting position in the storage shafts 14 to receive or deposit a respective Petri dish 15. Through a gap 18 in the outer circle of the storage shafts 14, the blade can also access the storage bins of the storage shafts of the inner circle. For this purpose, carousel 12 is rotated with the outer circle of the storage shafts 14 so that the gap 18 comes to lie in the region of the blade 17. Optionally, in the middle of the inner carousel 13, an auxiliary device 19 may be provided, which supports the work of the blade 17 and helps it to load the storage bins of the inner circle.

As further indicated in Fig. 1, at least two carriages 16, 16b are arranged one above the other at the lift column 16a in the embodiment shown. In FIG. 1, the lower carriage 16b is currently rotated to the transfer station 4. By using a plurality of carriages 16, 16b, which are independently movable vertically, the handling capacity can be increased. The lower carriage 16b operates the lower half of the storage device 1, and the upper carriage 16 the upper half.

As further seen, the storage device 1 in the illustrated embodiment has a user door 21 and an automatically open and closable auxiliary door 22. To transport a Petri dish from the interior 11 to the outside or in the reverse direction with the handling device 5, the auxiliary door 22nd open.

Outside the storage device 1, e.g. a table 23, which carries the components described below. The table 23 may be attached to the outside of the storage device 1.

The transfer station 4, which is also shown in Fig. 2, serves to take over at least one of the transfer device 5 discharged Petri dish, or temporarily record at least one Petri dish, which then lifted by the handling device 5 and in one of the storage bins of the storage device 1 is stored.

As shown in Fig. 2, the transfer station 4 comprises a transfer table 26, on which four relative to the transfer table 26 elevated pads 27 are arranged, on which a stored in the transfer station 4 Petri dish rests.

Fig. 5 shows the transfer table 26 with four editions 27 in detail. As can be seen, each support 27 forms a lateral, inclined ramp surface 28 on which the Petri dish is centered. At the ramp surface 28 includes a pad 29 on which rests the Petri dish. Pad pad 29 is preferably made of a high stiction material (i.e., higher stiction than the remaining material of pad 27), e.g. made of rubber, so that the deposited Petri dish (or its lid) in the manipulations described below, if possible, does not move.

In the embodiment according to FIG. 2, the transfer station 4 is arranged to be vertically movable on a lift 30 with drive 31. In contrast, the transfer station 4 in the embodiment of FIG. 1 is not adjustable in height but the transfer device 3 is arranged height-adjustable on a lift 30. Both variants are possible. It is important that the transfer device 3 (or its gripper described below) can be moved vertically relative to the transfer station 4.

The transfer device 3 has a rail 32 along which a head 33 along a horizontal axis 34 can be moved. For this purpose, a horizontal drive 35 is provided.

The head 33, the construction of Figs. 2 and 3 is clear, is pivotable about an axis parallel to the axis 34, to which a turning drive 34a is provided, and carries a gripper 36 with two fingers 37. The gripper 36 is thus to a pivotable horizontal axis and vertically relative to the transfer station 4 movable.

The gripper 36 has a finger drive 40, with which the two fingers 37 can be moved against each other, e.g. in a linear motion.

Fig. 4 shows a possible structure of a gripper 36 in detail. Each finger 37 has a shaft 38, wherein the two shafts 38 can be moved against each other. At least three oppositely directed elevations 43 are provided on the fingers 37 in order to grip the side walls of the petri dish 15. These serve to apply to the wall of the Petri dish 15 at defined points (or along defined generatrices) so that the Petri dish 15 can be picked up safely and without play.

Preferably, at least one of the elevations 43 is resiliently attached to the respective finger 37. In the embodiment according to FIG. 4, a spring 39 configured as a leaf spring is arranged on one of the fingers 37 for this purpose, which in turn holds a bent base part 42. At the base part 42 at least one of the elevations 43 is arranged. In the example shown, two elevations 43 are arranged on the base part 42.

Fig. 10 shows an alternative embodiment of the gripper 36, in which both fingers 37 each have a suspension 39, each carrying a base member 42. In this case, each base part 42 is provided with two elevations 43, since the suspensions 39 allow a certain tilting of the base parts 42 and thus four elevations 43 can be pressed without play against a not quite round Petri dish 15.

To understand the function of the present device, the construction of the Petri dishes 15 is first to be explained. Such a Petri dish is visible in FIG. It has a bottom 48 and a lid 49. As mentioned earlier, the sample to be tested is at the bottom 48, e.g. in a nutrient substrate adhered to the bottom 48, but the petri dish is stored in the storage device so that the bottom 48 is above the lid 49, i. rests on the cover 49. To analyze the Petri dish in the inspection device described in more detail below, the bottom 48 must be separated from the lid 49 and pivoted through 180 ° about a horizontal axis.

The bottom 48 has a round bottom surface 52, on the periphery of a peripheral, approximately cylindrical bottom wall 53 is provided. The cover 49 in turn also has a round cover surface 55, on whose circumference a cylindrical cover wall 56 is provided. The inner diameter of the cover wall 56 is slightly larger than the outer diameter of the bottom wall 53. If bottom 48 and lid 49 joined together, the bottom wall 53 engages in the top wall 56 and rests against the lid surface 55th

As mentioned, the Petri dishes 15 are stored in the storage bins of the storage device 1 with the lid 49 down. The transfer device transfers the Petri dishes 15 without turning between the storage bins and the transfer station 4. Thus, the Petri dishes come with the lid 49 down in the transfer station 4. Now, the gripper 36 is placed from above the bottom 48 of the Petri dish 15. The fingers 37 are approached each other so that they grasp the bottom 48 of the Petri dish 15 on the bottom wall 53. Now, the gripper 36 can be lifted relative to the transfer station 4, so that it pulls the bottom 48 of the lid 49. If at this time a drop from the ground dissolves 48, he falls into the lid.

Now, the gripper 36 is turned with the recorded Petri dish. This takes place vertically above the cover 49 located in the transfer station 4, so that in this phase any drops dissolving from the bottom 48 fall into the cover 49. Preferably, the bottom 48 is not moved from above the lid 49 until it has been turned more than 90 °.

Now, the gripper 36 can be moved with the recorded and turned lid 48 by means of the horizontal drive 35 to the inspection device 2. In the present embodiment is an optical inspection device with a camera 50, which is able to provide an image of a arranged in a measuring position 51 Petri dish. The measuring position 51 is located between the camera 50 and a light source 52 to produce images in transmitted light.

With the gripper 36, the recorded and turned lid 48 can be moved to the measuring position 51. For this purpose, the horizontal drive 35 is used, with which the head 33 can be moved along the rail 32. In this case, the device is designed such that the cover 48 of the Petri dish is held during the inspection by the inspection device with the gripper 36. It is therefore not necessary for the cover 48 to be deposited in the inspection device 2. This speeds up the process. Since the gripper engages the lid 48 only on the periphery, it does not interfere with the inspection process.

As already mentioned, the Petri dishes 15 are mounted in the storage device 1 in storage shafts 14. An advantageous storage shaft is shown in FIGS. 6 and 7.

The bearing shaft shown is essentially formed from a single sheet, which has been suitably cut and bent. In particular, the sheet forms a vertical rear wall 60 and two vertical side walls 61. At least on the side walls 61, preferably also on the rear wall 60, lateral trays 63 are arranged for receiving the Petri dishes. These are formed by bent tongues of the sheet of the back and side walls.

The rear wall 60 in each case via a transition region 64 in each side wall 61 via. This transition region extends in the embodiment of Fig. 6 and 7 obliquely to the sides, so that volume, which is not required in the rear region of the storage shafts 14 of the round Petri dishes 15, can be released. This allows a denser packing of the storage shafts 14 in a circle, as illustrated in Fig. 1, by the storage shafts can move closer together in a circle.

Since Petri dishes have a typical diameter of the order of 9 cm, the transition region 64 may have a flat, vertically extending portion 66 whose extent perpendicular to the longitudinal axis (vertical axis) of the bearing shaft 14 is at least 2 cm.

Since petri dishes are round, the transition region 64 can in principle also run rounded, as shown in phantom in Fig. 7 under reference numeral 66. In this case, if the radius of curvature of the transition region 64 corresponds approximately to that of the Petri dishes, an even denser packing of the storage shafts 14 is possible, but at a somewhat higher production cost. In this case, the radius of curvature of the transition region can be on average at least 2 cm, preferably at least 5 cm.

As is further apparent from FIGS. 6 and 7, the bottom 67 and the ceiling 68 of each bearing shaft 14 also extend integrally into the rear wall 60 and are made by bending from the same metal sheet as the rear wall 60 and the side walls 61.

The storage shafts 14 can be fixed in the storage device 1 in principle in any suitable manner. A preferred mounting variant is shown in Fig. 8dargestellt. Here, one or more openings 70 are provided in the bottom 67 (see Fig. 7), in which pins 71 engage. The pins 71 are connected to the base on which the respective storage shaft 14 stands. In the embodiment of FIG. 8, this pad is formed by one of the carousels 12 or 13. The pins 71 are tapered upwards.

From the top of the storage shafts of resilient, radially extending tongues 73 are held, which are fixed to a central region 74 of the storage device 1. The tongues 73 are advantageously resiliently biased and press from above onto the storage shafts 14. The tongues 73 may be screwed to the storage shafts 14.

Fig. 9 shows a second embodiment of the transfer device 3. It differs from that according to FIG. 1ddurch that two transfer stations 4, each with its own transfer table 26 are provided one above the other. These can be moved vertically on the lift 30, preferably with a common lift drive 31. Each of the transfer stations 4 can be moved to the height in which they can interact with the gripper 36 and the handling device 5. Thus, e.g. a first Petri dish are analyzed while its lid is in the one transfer station 4, while the transfer device 5 of the other transfer station 4 takes a Petri dish or feeds her a Petri dish.

While preferred embodiments of the invention are described in the present application, it should be clearly understood that the invention is not limited thereto and may be embodied otherwise within the scope of the following claims.

Claims (20)

A device for storing and handling Petri dishes (15), wherein the Petri dishes (15) have a bottom (48) and a lid (49), wherein on a periphery of the bottom (48) has a bottom wall (53) is arranged a bearing device (1) for storing the petri dishes (15) with the lid (49) down, an inspection device (2) for the automated inspection of Petri dishes (15) without covers (49) and a transfer device (3) for transferring the petri dishes (15) between the storage device (1) and the inspection device (2), characterized in that the transfer device (3) has a gripper (36), with which in each case a Petri dish (15) without the lid (49) laterally on the bottom wall (53) are gripped. 2. Device according to claim 1, wherein the transfer device (3) has at least one transfer station (4) for receiving a Petri dish (15) with the lid (49) down, from each of which a Petri dish (15) without the lid (49). from the gripper (36) is graspable. 3. Device according to claim 2, wherein the transfer device (3) has a turning drive (34a), with which the gripper (36) with a recorded bottom (48) of a Petri dish (15) vertically above the in the transfer station (4) lying lid (49) is reversible, in particular by more than 90 ° is reversible. 4. Device according to one of claims 2 or 3, wherein the device comprises a lift drive (31), with which the gripper (36) relative to the transfer station (4) is vertically displaceable. 5. Device according to one of claims 2 to 4, wherein the transfer device (3) has a horizontal drive (35), with which the gripper (36) of the transfer device (3) to the inspection device (2) and back is movable. 6. Device according to one of claims 2 to 5, wherein the device comprises two transfer stations (4), both of which are movable, and in particular wherein a common lift drive (31) for both transfer stations (4) is provided. A device according to any one of the preceding claims, wherein the device is adapted to hold the lid (49) with the gripper (36) during inspection by the inspection device (2). 8. Device according to one of the preceding claims, wherein the storage device (1) has a plurality of storage spaces for Petri dishes (15) with the lid (49) down and a transfer device (5) to the Petri dishes (15) between the storage bins and the transfer device (3) to transport, and in particular wherein the transfer device for transferring the Petri dishes (15) between the storage bins and the transfer station (4) without turning the Petri dishes (15) is designed. 9. The apparatus of claim 8, wherein the storage bins are formed by a plurality of storage shafts (14), wherein each storage shaft (14) has a plurality of storage bins one above the other, and in particular wherein the storage shafts on at least one carousel (12, 13) are arranged. 10. Device according to one of claims 8 or 9, wherein the handling device (5) has two vertically movable carriage (16, 16 b), and in particular wherein the carriage (16, 16 b) on a common lift column (16 a) are arranged one above the other. 11. Device according to one of the preceding claims, wherein the gripper (36) has two mutually movable fingers (37) having a plurality, preferably a total of three or, mutually directed elevations (43) for acting on the wall of the Petri dish (15). 12. The apparatus of claim 11, wherein at least one of the fingers (37) has a suspension (39) which carries a base part (42), wherein the base part (42) at least one of the elevations (43) is arranged. 13. A storage device, in particular for use in the device according to one of the preceding claims, wherein the storage device has at least one storage shaft (14), each storage shaft (14) has a plurality of storage bins for receiving a respective laboratory object on top of each other, wherein in a bottom (67). each bearing shaft (14) at least one opening (70) is arranged, in which at least one pin (71) of a pad (12, 13) of the bearing shaft engages, and wherein the bearing shafts (14) from above by means of resilient tongues (73) are held , 14. Storage device according to claim 13, wherein the storage device has at least one carousel (12, 13), which forms the base for the storage shafts, wherein the storage shafts are arranged in at least one circle on the at least one carousel (12, 13). 15. A bearing device according to claim 14, wherein the tongues (73) extend radially and are fastened to a central region (74) of the bearing device. 16. Bearing device according to one of claims 14 or 15, wherein the tongues (73) are resiliently biased and press from above onto the storage shafts (14). 17. Bearing shaft, in particular for use in the device or the bearing device according to one of the preceding claims, wherein the bearing shaft has a rear wall (60) and two side walls (61), and wherein at least on the side walls (61) lateral shelves (63) Receiving the Petri dishes (15) are arranged, characterized in that the rear wall (60) merges via a respective transition region (64) in each side wall (61), wherein the transition region (64) is rounded and / or obliquely to the rear wall (60 ) and the adjacent thereto side wall (61). 18. Storage shaft according to claim 17, wherein the intermediate region is rounded with a radius of curvature of at least 2 cm, preferably at least 5 cm. 19. Bearing shaft according to claim 17, wherein the intermediate region has a substantially planar portion, which has an extension of at least 2 cm perpendicular to a longitudinal axis of the bearing shaft. 20. Storage shaft according to one of claims 17 to 19, wherein also on the rear wall shelves (63) for receiving the Petri dishes (15) are arranged.