Tempering block module and apparatus for the thermal treatment of samples

Abstract

The present disclosure relates to a tempering block module for the thermal treatment of samples, comprising: a tempering block; and an ejection mechanism for lifting reaction vessels off the tempering block, the ejection mechanism including first and second ejection plungers that are movably mounted in the tempering block module perpendicular to the tempering block from a first position, retracted into the tempering block module, into a second position, extended out of the tempering block module, and wherein the tempering block module includes a first plunger drive connected to the first ejection plunger for driving the movement of the first ejection plunger and a second plunger drive, different from the first plunger drive, connected to the second ejection plunger for driving the movement of the second ejection plunger from the first to the second position or from the second to the first position.

Claims

1. A tempering block module for a device for thermal treatment of samples, the tempering block module comprising: a tempering block; a tempering element; a heat sink; an ejection mechanism configured to lift reaction vessels disposed on the tempering block from the tempering block and including a first ejection plunger and a second ejection plunger, wherein the first ejection plunger and the second ejection plunger are movably mounted in the tempering block module perpendicular to a plane in which the tempering block is arranged such that the first ejection plunger and the second ejection plunger are movable from a retracted first position within the tempering block module to a second position extended out of the tempering block module; a first plunger drive operatively connected to the first ejection plunger and configured to drive movement of the first ejection plunger from the first position to the second position or from the second position to the first position; and a second plunger drive operatively connected to the second ejection plunger and configured to drive movement of the second ejection plunger from the first position to the second position or from the second position to the first position, wherein the first plunger drive and the second plunger drive are each driven and controlled independently, thereby enabling different force, different speed and/or different timing therebetween.

2. The tempering block module of claim 1, further comprising a plurality of ejection plungers and a plurality of plunger drives, one plunger drive per ejection plunger, such that each plunger drive is operatively connected to one of the plurality of ejection plungers and configured to drive the movement of the corresponding ejection plunger from the first position to the second position and from the second position to the first position.

3. The tempering block module of claim 1, wherein the first and second ejection plungers are arranged on a periphery of the tempering block.

4. The tempering block module of claim 1, wherein the first and second ejection plungers are mounted directly or indirectly on the heat sink via one or more further components.

5. The tempering block module of claim 1, wherein the first and second plunger drives are embodied as linear motors.

6. A device for thermal treatment of samples, the device comprising: a base unit including a receiving region configured for receiving one or more reaction vessels; a tempering block module disposed in the base unit, the tempering block module comprising: a tempering block; an ejection mechanism configured to lift reaction vessels disposed on the tempering block from the tempering block and including a first ejection plunger and a second ejection plunger, wherein the first ejection plunger and the second ejection plunger are movably mounted in the tempering block module perpendicular to a plane in which the tempering block is arranged such that the first ejection plunger and the second ejection plunger are movable from a retracted first position within the tempering block module to a second position extended out of the tempering block module; a first plunger drive operatively connected to the first ejection plunger and configured to drive movement of the first ejection plunger from the first position to the second position or from the second position to the first position; and a second plunger drive operatively connected to the second ejection plunger and configured to drive movement of the second ejection plunger from the first position to the second position or from the second position to the first position; and a cover configured to close off the receiving region and to be moved from an open third position to a closed fourth position, wherein the cover includes a cover plate having a front surface, wherein the front surface configured to apply a pressing force against reaction vessels disposed on the tempering block when the cover is in the fourth position, wherein the first plunger drive and the second plunger drive are each driven and controlled independently, thereby enabling different force, different speed and/or different timing therebetween.

7. The device of claim 6, further comprising: at least one connecting element connected to the cover; and a cover drive disposed in the base unit and coupled to the at least one connecting element as to drive the movement of the cover from the third position to the fourth position and/or from the fourth position to the third position, wherein the cover drive is coupled to the at least one connecting element such that, during the movement from the third position to the fourth position, the cover with the cover plate, in a first movement segment, is initially moved from the third position into a fifth position in which the front surface of the cover plate extends parallel to and spaced from the tempering block, and that the cover with the cover plate, in a subsequent second movement segment, is moved from the fifth position in a direction of a shared normal of the front surface and a plane in which the tempering block is arranged, the second movement segment continuing toward the receiving region of the base unit until the cover has reached the fourth position.

8. The device of claim 7, wherein the cover drive is adjustable and/or controllable for adjusting the pressing force applied perpendicularly on the front surface of the cover plate and applied to the cover and the cover plate via the connecting elements during the second movement segment.

9. The device of claim 7, further comprising a drive control connected or connectable to the first and second plunger drives of the tempering block module and configured to control the first and second plunger drives independently of one another based on a specification by a user or a higher-level control connected to the drive control.

10. The device of claim 9, wherein the cover drive includes an electric motor, and wherein the drive control is configured to adjust the pressing force that the cover drive exerts on the cover and the cover plate via at least one connecting element.

11. The device of claim 9, wherein the drive control is configured, in a first operating mode, to control the first and second plunger drives such that the first and second ejection plungers are moved to the second position and/or are moved back to the first position at different times.

12. The device of claim 9, wherein the drive control is configured, in a second operating mode, to drive the first and second plunger drives such that the first and second ejection plungers are moved synchronously to the first position and/or the second position.

13. The device of claim 9, wherein the drive control is configured to control the cover drive and the first and second plunger drives so as to be coordinated with each other such that, when the cover is moved from the fourth position to the first position, the first and second ejection plungers are moved synchronously or successively from the first position to the second position.

14. A method for removing a microtiter plate from a tempering block of a device for thermal treatment of samples, the method comprising: providing the device for the thermal treatment of samples, the device including: a base unit; a tempering block module, including the tempering block, disposed in the base unit; moving a cover, including a cover plate and configured to close the base unit, along a first movement segment from a closed position, in which a front surface of the cover plate exerts a pressing force against the microtiter plate, into an intermediate position in which the front surface of the cover plate extends parallel to and is spaced from the microtiter plate; subsequently, moving the cover to an open position; and moving a first ejection plunger and a second ejection plunger, which are movably mounted in the tempering block module perpendicular to a plane in which the tempering block is arranged, from a first position retracted into the tempering block module to a second position extended from the tempering block module, using a first plunger drive to move the first ejection plunger and using a second plunger drive to move the second ejection plunger, wherein the first ejection plunger and second ejection plunger strike against an edge of the microtiter plate during movement and lift the microtiter plate from the tempering block, wherein the first plunger drive and the second plunger drive are each driven and controlled independently, thereby enabling different force, different speed and/or different timing therebetween.

15. The method of claim 14, wherein the movement of the cover and the movement of the first ejection plunger and second ejection plunger occur simultaneously and synchronously such that the cover plate rests against the microtiter plate until the first and second ejection plungers have reached the second position.

16. The method of claim 14, wherein the movement of the cover is effected using a cover drive controlled by a drive control, and wherein the first and the second plunger drives are likewise controlled by the drive control.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure is explained in further detail below on the basis of the exemplary embodiment shown in the figures. Shown are:

(2) FIGS. 1a-1d show perspective views of a device for thermal treatment of samples when the cover is in different positions;

(3) FIG. 2 shows a perspective detail view of a tempering block module of the device shown in FIGS. 1a-1d;

(4) FIGS. 3a and 3b show detailed side views of the tempering block module shown in FIG. 2 with ejection plungers in a first, retracted position (3a) and in a second, extended position (3b);

(5) FIGS. 4a-4e show side sectional views of the device according to FIGS. 1a-1d in different positions of the cover with a first sectional plane;

(6) FIGS. 5a and 5b show side sectional views of the device in accordance with FIGS. 1a-1d with a second sectional plane; and

(7) FIG. 6 shows a front sectional view of the device in accordance with FIGS. 1a-1d with a third sectional plane extending perpendicularly to the first and second sectional planes.

DETAILED DESCRIPTION

(8) The figures schematically show an exemplary embodiment for a device 1 with a tempering block module 23 for the thermal treatment of samples, a so-called thermocycler. Identical reference numerals denote identically configured elements of the device. A plurality of identically acting modifications are possible without departing from the inventive idea.

(9) FIGS. 1a-1d show perspective views of the device 1. It possesses a base unit 2 and a cover 3 which is shown in various positions in FIGS. 1a-1c. A tempering block module 23 with a tempering block 13 is arranged in the base unit (FIG. 1d). The tempering block module 23 has on its upper side a cover frame 30 which leaves the tempering block 13 exposed. The area arranged above the tempering block 13 forms a receiving area 4 in which reaction vessels with liquid samples to be thermally treated can be arranged. The tempering block 13 is made of a metal having high thermal conductivity, for example silver or aluminum, and has a plurality of receptacles for reaction vessels.

(10) FIGS. 1a, 1c and 1d show a rectangular microtiter plate 5 arranged in the receiving area 4, which has a plurality of depressions serving as reaction vessels. Typically, such microtiter plates are made of plastic. In the present example, the microtiter plate 5 is placed on the tempering block 13 so that the depressions formed in the microtiter plate 5 serving as reaction vessels project into the receptacles.

(11) In the example shown here, the receptacles are designed as cylinders, which are situated upright on a base surface of the tempering block 13. Alternatively, the tempering block 13 can also be designed substantially cuboid with depressions formed in one of its surfaces as receptacles for reaction vessels or with a flat surface. The receptacles, or the upper edges or openings thereof, are essentially located in a horizontal plane, which is also referred to here as the plane in which the tempering block 13 is oriented. The microtiter plate 5 is oriented parallel to this plane during operation of the device. When the front surface of the heatable cover plate 7 bears against the microtiter plate 5, it is likewise oriented parallel to this plane.

(12) The cover 3 is connected to the base unit 2 via two connecting elements 6, which in the present exemplary embodiment are designed as connecting arms. The connecting arms 6 are coupled to a cover drive, which is arranged in the base unit 2 and will be described in more detail below, and which can move the cover 3 for automatically opening and closing the base unit 2. Arranged in the cover 6 is a heatable cover plate 7, the front surface of which points towards the receiving area 4 and is intended to rest against the reaction vessels formed in the microtiter plate 5 when the cover 3 is closed.

(13) In FIG. 1a, the cover 3 is in an open first position in which the cover plate 7 is inclined with respect to the surface of the microtiter plate 5. In this position of the cover 3, unimpeded access to the receiving area 4 is possible, for example for insertion or removal of the microtiter plate 5. This insertion and removal of the microtiter plate 5 can take place, for example, by means of a robot gripper arm. The device 1 can be operated completely automatically in combination with a robot operating system. In FIG. 1c, the cover 3 is in a closed second position. In this position of the cover 3, the front surface of the cover plate 7 bears against the surface of the microtiter plate 5 with a specifiable pressure so that the microtiter plate 5 is pressed against the tempering block 13 for uniform heat transfer. At the same time, the cover plate 7 closes the reaction vessels formed in the microtiter plate 5.

(14) FIG. 1b shows a third position of the cover 3, which forms an intermediate position during the movement of the cover 3 from the first into the second position or also during the movement of the cover 3 from the second into the first position. In this third position, the cover 3 is oriented parallel to the microtiter plate 5 or to the tempering block arranged beneath the microtiter plate 5, and is spaced from the surface of the microtiter plate 5.

(15) The device 1 is designed in such a way that a movement of the cover 3 from the first, open position into the second, closed position extends over the third position, that is, the cover 3 is initially brought from the first into the third position in an arc-shaped movement in a first movement segment. From this third position, the cover 3 is moved vertically in a second movement segment, i.e. perpendicular to the plane in which the tempering block is oriented, and thus also perpendicular to the surface of the microtiter plate 5, towards the latter and is thus brought into the second, closed position.

(16) A movement of the cover 3 in the opposite direction, that is, from the second, closed position into the first, open position, likewise takes place via the third position, in that, in a first segment of this movement, the cover 3 is moved away from the microtiter plate 5 perpendicularly to the surface thereof, until it reaches the third position. In a subsequent second movement segment, the cover 3 is moved from the third position to the first position in an arc-shaped movement.

(17) The device 1 has an ejection mechanism which serves to lift the microtiter plate 5 out of the tempering block 13 after completion of the thermal treatment, in order to make it easier for a robot gripper arm to remove the microtiter plate 5 from the receiving area 4. FIG. 1d shows 30 ejection plungers 26 protruding from the cover frame. In the exemplary embodiment shown here, an ejection plunger 26 is arranged on each side edge of the cuboid tempering block 13. The ejection plungers 26 can be moved back and forth between a position retracted into the tempering block module 23 (FIG. 1a) and a position extended from the tempering block module 23 perpendicular to a surface in which the tempering block 13 is arranged or perpendicular to the surface of the microtiter plate 5. When moving from the retracted to the extended position, the ejection plungers 26 strike the edge of the microtiter plate 5 with their upwardly directed front face against an underside and lift it out of the tempering block 13 with their further movement until the extended position is reached.

(18) FIG. 2 shows a schematic perspective longitudinal section view of the tempering block module 23. The tempering block module 23 is arranged in the upper region of the base unit 2. In addition to the tempering block 13, it has a tempering device with one or more tempering elements 24 and a heat sink 25 arranged on the side of the tempering elements 24 facing away from the tempering block 13. The heat sink 25 is covered by the cover frame 30. The tempering elements 24 may comprise thermoelectric elements, for example Peltier elements.

(19) A control unit may be provided in base unit 2 to control or regulate the thermoelectric elements 24 to pass through predefined temperature cycles in order to carry out polymerase chain reactions. The temperature control system can also be implemented at least partially in an external control unit connected to the thermoelectric elements 24 via the interface 2. The temperature control system is designed in the conventional way and is therefore not described in detail here.

(20) In the exemplary embodiment shown here, four ejection plungers 26 are arranged in the tempering block module 23, each at the corners or side edges of the tempering block 13. Each ejection plunger 26 is assigned its own plunger drive 27. The plunger drives 27 are mounted on the heat sink 25 either directly or indirectly via one or more other components. They are operatively connected to the ejection plungers 26 for driving their movement from their retracted position in the tempering block module 23 to a position extended from the tempering block module 23 and in the opposite direction.

(21) FIGS. 3a and 3b show the tempering block module 23 with the tempering block 13, the microtiter plate 5 placed thereon, and two of the four ejection plungers 26 in a longitudinal sectional view.

(22) The ejection plungers 26 are shown in FIG. 3a in their first position retracted from the tempering block module 23 and in FIG. 3b in their second position extended out of the tempering block module 23. The ejection plungers 26 are arranged at the periphery of the tempering block 13 so that the ejection plungers 26 strike the underside of the microtiter plate 5 when they move from the retracted position to the extended position and take the microtiter plate 5 along with them when they move further upwards. When the extended position of the ejection plungers is reached, the entrained microtiter plate 5 is lifted off the tempering block 13 in such a way that an automatically operated robot gripper arm can easily grip it. In the present exemplary embodiment, the ejection plungers 26 are arranged at the corners of the rectangular base area of the tempering block 13. It is possible to provide additional ejection plungers along the sides of the base area or to provide ejection plungers only on the sides. Of course, base areas for the tempering block 13 other than rectangular ones are also conceivable. The ejection plungers are then correspondingly arranged at suitable positions along the periphery of the tempering block.

(23) The plunger drives 27 can be designed as electric drives, but also as pneumatic or hydraulic drives. In this example, the plunger drives 27 each comprise an electric motor 28, which is coupled to the ejection plunger 26 via a spindle 29 converting a rotational movement into a linear movement. The plunger drives 27 can be controlled individually by means of a drive control. Such a drive control configured for individual actuation of the plunger drives 27 can be arranged, for example, at least partially in the base unit 2.

(24) Thus, it is possible to implement different movement patterns of the ejection plungers 26 by means of the drive control. For example, the ejection plungers 26 can be moved synchronously so as to keep the microtiter plate 5 permanently in an exactly horizontal orientation during the ejection movement. It is also possible to move only individual ejection plungers 26.

(25) During the thermal treatment of the sample, the plastic material of the microtiter plate 5 at the tempering block 13 may start to partially flow and adhere to the receptacles of the tempering block 13. So as to detach the liquid-filled reaction vessels from the receptacles without excessive vibrations, the drive control unit can advantageously be configured to activate the plunger drives 27 in such a way that these alternately reach the extended position, so that the microtiter plate 5 is lifted off the tempering block 13 in a pulsating or wave-like movement.

(26) In FIGS. 4a-4e, the device 1 is shown schematically in a sectional view along a first vertical sectional plane with different positions of the cover 3. In this view, the tempering block 13 can also be seen in FIGS. 4a, 4b, 4c and 4e.

(27) A cover drive 8 for moving the cover 3 is arranged in the base unit 2. The cover drive 8 is coupled to the connecting elements 6 via a respective coupling device, which will be described in more detail below. In the sectional view shown in FIGS. 4a-4e, only one of the coupling devices can be seen which couples the cover drive 8 to one of the connecting elements 6. A coupling device, which is designed in an analogous manner (symmetrically to the coupling device shown here) and which couples the cover drive 8 to the second connecting element 6 arranged on the opposite side of the cover, is arranged on the opposite side of the base unit. The visible coupling device will be described hereafter.

(28) The cover drive 8 comprises a motor (not visible in FIGS. 4a-4e) and a drive shaft (not visible in FIGS. 4a-4e) rotatable about an (imaginary) rotational axis R. The drive shaft is rigidly connected to the lever arm 9 extending perpendicularly to the rotational axis R. A linear guide 10 in which the lever arm 9 is guided is arranged on the connecting element 6. The linear guide 10 is attached to the connecting element 6 so as to rotate about an (imaginary) second rotational axis extending parallel to the rotational axis R.

(29) A guide plate 11, which is oriented perpendicularly to the rotational axis R of the drive shaft, is arranged in the base unit 2. A guide slot 12, which has a first, arc-shaped section and a second, linear section oriented perpendicularly to the microtiter plate 5, is formed in the guide plate 11. The movement of the connecting element 6 caused by the cover drive 8 is guided in the guide slot 12 in the guide plate 11. To this end, the connecting element 6 has two pins 31 which are guided in the guide slot 12. As mentioned, a mirror-image coupling device is located on the opposite side of the cover drive 8 in the base unit 2 to drive and guide the movement of the other connecting element 6. Instead of the guides described here, other mechanisms can be used which convert a rotational movement of the drive shaft into a linear movement of the connecting elements 6.

(30) In FIG. 4a, the cover 3 is in the first, open position. The pins 31 of the connecting element 6 are located at a first end of the guide slot 12. A rotation of the drive shaft about the rotational axis R causes a movement of the pins 31 along the arc-shaped section of the guide slot 12 via the guidance of the lever arm 9 in the linear guide 10. This movement results in an arcuate movement of the lid 3 over the position shown in FIG. 4b. This movement causes the angle of the cover 3 or of the cover plate 7 arranged therein to become increasingly smaller with respect to the plane in which the tempering block 13 is arranged, until the cover 3 and the cover plate 7 are oriented parallel to this plane or to the microtiter plate 5, but are still at a distance from the microtiter plate 5. This ends the first movement segment, and the third position of the cover 3 is reached, FIG. 4c. The further movement of the drive shaft causes a linear downward movement of the connecting element 6 in the guide slot 12 via the linear guide 10, so that the cover 3 and the cover plate 7 arranged therein move in a perpendicular direction towards the microtiter plate 5, in a manner oriented parallel to the microtiter plate 5, until the front surface of the cover plate 7 strikes against the microtiter plate 5. Ideally, no horizontal force components (shearing forces) are exerted on the microtiter plate 5. There is thus no risk that one side of the microtiter plate 5 will be lifted off or displaced on the tempering block 13.

(31) A pressing force of the front surface of the cover plate 7 against the microtiter plate 5 is caused by a further rotational movement of the drive shaft. This can be predefined by the torque of the drive shaft or by the force which is accordingly exerted on the connecting elements 6 by the cover drive 8 via the coupling device. When the cover plate 7 rests against the microtiter plate 5 with the predefined contact pressure, the second position of the cover 3 (FIG. 4d) is reached.

(32) The rotational movement of the drive shaft in the opposite direction causes a corresponding movement of the cover 3 and the cover plate 7 running in the opposite direction from the second position via the third position into the first position, guided in the guide slot 12.

(33) Alternative embodiments of the coupling unit between the cover drive 8 and the connecting elements 6 or the cover 3 are conceivable. For example, instead of the linear guide 10 for the lever arm 9, a combination of a guide slot and an elongated hole can also be used for coupling the lever arm 9 to the connecting element.

(34) FIGS. 5a and b show further schematic sectional views of the device 1, wherein the second sectional plane considered here extends parallel to the first sectional plane used in FIGS. 4a-4e. The cover drive 8 can be seen in more detail in these sectional views. The cover drive 8 comprises a controllable motor 14, for example an electric motor, which can be connected to a drive control unit provided in the base unit itself or outside the base unit. An interface 15 is provided in the base unit for optional connection to an external drive control. In the present example, the cover drive 8 further comprises a, preferably self-locking, gear system 16 which can be actuated by the motor 14. In the present exemplary embodiment, the gear system 16 is designed as a worm gear mechanism, but other embodiments which are able to cause the rotational movement of a drive shaft are also possible. The gear system 16 in the present example comprises a gear wheel 17 (worm gear) and a helical worm shaft 18, the rotational movement of which causes the gear 17 to rotate. The gear wheel 17 is rigidly connected to the drive shaft 19 already mentioned above in connection with FIGS. 4a-4e (visible in FIGS. 5a and 5b), which drives the movement of the cover 3 via the lever arm 9, the linear guide 10 and the connecting element 6 guided in the guide slot 12.

(35) The front housing wall 20 of the housing of the base unit 2 is designed removable. In this way, the interior of the housing, especially the worm shaft 18, is accessible from outside for maintenance or repair. In the event that the cover 3 cannot be opened automatically by means of the drive control, for example in the case of a defect, it is possible to actuate the worm shaft 18 manually, for example by means of a screwdriver, and to thus open the cover 3 manually to reach the microtiter plate 5 and the samples contained therein.

(36) The sectional views of FIGS. 5a and 5b also show the design of the cover 3 in detail. As described, the cover 3 contains the cover plate 7, which can be heated by means of a heating module. This is coupled via pressure springs 21 to a pressing panel 22 which in turn is rigidly connected to the connecting elements 6. The force exerted by the cover drive 8 on the connecting elements 6 is transmitted to the cover plate 7 via the pressure springs 21. The heating module is designed in a conventional manner and can be connected to a power supply via the interface 15 of the base unit 2.

(37) FIG. 6 shows a schematic longitudinal sectional view of the device 1 when the cover 3 is closed (in the second position) along a third sectional plane which extends perpendicularly to the first (FIGS. 4a-4e), and second (FIGS. 5a and 5b) sectional planes. In this view, it is apparent that the coupling device between the gear system 16 and the connecting elements 6 has a mirror-image design with respect to an (imaginary) plane of symmetry extending through the gear wheel 17 of the gear system 16. Each of the connecting elements 6 is therefore coupled to the drive shaft 19 via a lever arm 9 guided in a linear guide 10, wherein the movement of the connecting elements 6 is guided in each case by a pin, which can be moved in a guide slot of a guide plate 11 and connected to one of the connecting elements 6 (not visible in FIG. 6).

(38) In the very advantageous exemplary embodiment described here, the drive control unit is designed both to control the cover drive 8 for the movement of the cover 3 and to control the plunger drives 27 for the movement of the ejection plungers 26. In this case, the drive control unit can be designed to match the movement of the cover and the movement of the ejection plungers 26 according to a predefined operating program. Thus, when the cover 3 is lifted from the first position into the third position, the drive control unit at the same time can move the ejection plungers 26 of the mechanism described in more detail in FIGS. 2, 3a and 3b into the extended position so that the microtiter plate 5 remains pressed against the front surface of the cover plate 7 while it is being lifted off the tempering block 13. Thus, the reaction vessels remain additionally held during the lifting of the microtiter plate 5 by the cover plate 7 and are hence protected against sudden movements when detached from the tempering block.

(39) As mentioned above, an external drive control connected to the motor 14 via interface 15 can be provided to control the cover drive 8 and the previously described plunger drives 27 of the ejection mechanism for the microtiter plate 5. However, it is also possible for the drive control to be arranged at least partially in the base unit 2, for example in the form of a circuit implemented on a circuit board arranged in the base unit 2. The drive control unit comprises at least one processor, memory elements, and one or more operating programs stored in one or more of the memory elements and executable by the processor. The operating program is, or the operating programs are, used to operate and control the device 1, for example for controlling the cover drive 8. The drive control unit can be configured, by means of an operating program, to read in an identifier of a reaction vessel, for example a microtiter plate 5, to be inserted into the receiving region 4, to determine, based on the identifier, a pressing force suitable for the specific reaction vessel with which the cover plate 7 is to bear against the reaction vessel when the cover 3 is in the second position, and to control the cover drive 8 for applying the determined pressing force.

(40) The drive control be set up by means of the operating program in order to move the movement of the ejection plunger 26 according to an operating mode selected from a plurality of possible operating modes, especially in coordination with a concurrent cover movement. Thus, as already mentioned, the drive control can actuate the ejection plunger 26 simultaneously and synchronously in a first operating mode by means of the plunger drives 27 so that all ejection plungers reach their extended position simultaneously, or are simultaneously moved into the retracted position. In a second mode of operation, the drive control may actuate the ejection plunger 26 to move it sequentially and/or alternately to its extended and retracted positions to realize a pulsating or undulating movement of the microtiter plate.

(41) The device described here is suitable for automatic actuation, provides high operational reliability, and has a space-saving and simple design.