Technical Field

The present application concerns a container for accommodating a plurality of petri- dishes and sequentially presenting the petri-dishes for use, and to a process for transferring petri-dishes from and to such container. In particular, the present application concerns the field of testing in pharmaceutical and food processing and more particularly environmental monitoring of clean or ultra clean closed processing areas or production isolators (these terms will be used interchangeably in this specification). It is also applicable to other processing situations where cleanness of a processing area or environment is to be determined and monitored, for example in the field of semiconductor, electronics or aircraft manufacturing.

Background

In order to monitor environmental conditions in closed processing areas of the above type it is common practice in passive air sampling to place one or more media plate/plates in an activity zone of the production area and expose them to the surrounding air such that they can capture the maximum amount of particles in the surrounding air. Larger particles tend to settle faster on the plates due to gravitational force. Smaller particles take some time in settling due to factors such as air currents. Media plates work best in still areas. The microorganisms from the air may settle on the media plates alone or in colonies.

In active monitoring of the atmosphere, for example air, in closed production areas a microbial air sampler is used to force air into or onto a collection medium over a specified period of time. The collection medium can be a common petri-dish, for example including a nutrient agar-based test media or other suitable test media depending on the need.

The collection media, for example in the form of the media plates, petri-dishes or settle plates (the terms will be used interchangeably in this specification), have to be transferred repeatedly into the production area and removed therefrom for further handling and evaluation and/or handled inside an isolated production area. This is commonly done in a manual process where one or more plates or petri-dishes are conveyed manually through a sterile transfer port into and from the interior of the production area and inside the production area depending on the respective process. However, the manual handling of the petri-dishes involves a high risk of contamination when handling the media plates, i.e. that lids are inadvertently opened, displaced or removed from their media plates during handling involving introduction, installation and removal, thereby compromising the detection result, in particular when a plurality of them are handled in batches. Further, humans are also the main source of airborne biocontamination inside an isolated production area for all passive and active biomonitoring sampling processes.

What is desired is a packaging for a plurality of media plates, petri-dishes or settle plates, i.e. a batch, that supports an at least partly or preferably fully automated process that does not necessarily involve human handling steps for introducing, sampling and removing the media plates into and from the closed sterile processing areas or production isolators as well as presenting and collecting the individual media plates inside closed sterile processing areas or production isolators.

It is furthermore preferable to provide a packaging for such a partly or fully automated process with which it is possible to use standard media plates available on the market, preferably the so-called petri-dishes.

It is furthermore preferable to provide a packaging that is compatible with the application of the transfer principle of docking a device holding one or more objects to be transferred to a standard rapid transfer port (RTP) of an isolator or other comparable solutions and transferring the objects from the device into the isolator and vice versa.

The present application also aims at providing a packaging with which a plurality of media plates, petri-dishes or settle plates can be introduced into and removed from a closed processing area or production isolator and with which the media plates can be individually processed inside or outside such processing area or production isolator for the purposes of air sampling without compromising the sterility, preferably without requiring a large space or footprint inside the isolator. The present application further aims at providing a packaging for a batch of media plates, petri-dishes or settle plates for use in sampling air in a production isolator by means of a sterile and effective process, preferably with a large degree of automation involving, for example, a robot gripper, that does not exclude a manual handling if needed, and which is capable of keeping the batch together for traceability and documentation and evaluation purposes.

Summary

The present inventors have now surprisingly found that the above objects may be attained either individually or in any combination by the container for accommodating a plurality of petri-dishes as defined by claim 1, and the process as defined by claim 13 for transferring petri-dishes from and to such container. Preferred embodiments of the present container and process are defined in the dependent claims.

A container for accommodating a plurality of petri-dishes as defined herein thus comprises: a cylindrical cartridge housing configured to receive the plurality of petri-dishes in a stack aligned with an axial direction of the cartridge housing in an interior space of the cartridge housing such that the stack of petri-dishes can be moved in the axial direction within the interior space, wherein a first axial end of the cartridge housing has a first opening dimensioned so that the petri-dishes can be sequentially/consecutively exposed from the cartridge housing by moving the stack in the axial direction, wherein a second axial end of the cartridge housing has a second opening dimensioned so that the petri-dishes can be sequentially/consecutively inserted into the interior space of the cartridge housing in the axial direction, wherein a first stopper is provided at the first opening and a second stopper is provided at the second opening, the first and second stoppers configured to allow a petri-dish to pass into and out from the interior space through the respective first and second openings in the axial direction; wherein the container comprises a first plug that is either configured to be inserted into the interior space of the cartridge housing in the axial direction through the second opening passing the second stopper in at least one orientation, or that is provided in the interior space, the first plug being configured to be moved in the axial direction within the interior space with the stack of petri-dishes, and configured to be prevented by the first stopper from being removed from the interior space through the first opening in at least one orientation, and wherein the container comprises a second plug that is configured to be inserted into the interior space of the cartridge housing in the axial direction through the second opening passing the second stopper in at least one orientation but to be prevented from being removed through the second opening in the opposite axial direction by the second stopper in the at least one orientation, the second plug being configured to be moved in the axial direction within the interior space with the stack of petri-dishes, and configured to be removed from the interior space through the first opening passing the first stopper in at least one orientation.

Preferably, the first and/or second plug is/are formed so as to serve as a cover that can substantially close the first and/or the second opening in one orientation of the respective plug.

Preferably, the first and/or the second stopper is/are integrally formed with the cartridge housing or is/are removably provided at the cartridge housing.

Preferably, the container further comprises a one-way gate at the second opening that is configured to allow insertion of the petri-dishes into the interior space in the axial direction and to prevent removal from the interior space in the opposite axial direction.

Preferably, the one-way gate is a part of the container or is part of a holder for the container.

Preferably, the one-way gate comprises a plurality of retainers distributed about the circumference of the second opening and configured to move between a first position where the retainers partially block the second opening to prevent removal of the petri- dishes from the interior space in the opposite axial direction, and a second position where the retainers allow insertion of the petri-dishes through the second opening into the interior space in the axial direction.

Preferably, the retainers are formed by lever-like elements pivotally supported such that the lever-like elements protrude radially inward in a first pivoted position and are radially retracted in a second pivoted position. Preferably, the retainers are provided so as to be biased into the first position and are movable against the bias into the second position.

Preferably, the cylindrical cartridge housing is provided with one or more opening/openings for allowing air circulation between the outside environment and the interior space.

Preferably, the container further comprises a plurality of petri-dishes in a stack received in the interior space of the cartridge housing in a sterile environment.

Preferably, the first and second plugs are received in the interior space of the cartridge housing and are stacked below the bottom of the stack of petri-dishes with the first plug being arranged at the outermost position.

Preferably, the first plug is arranged at the first end of the cartridge housing stacked above a top of the stack of petri-dishes in an orientation in which it is not prevented from being removed from the first opening by the first stopper, and the second plug is received in the interior space of the cartridge housing stacked below a bottom of the stack of petri-dishes in an orientation in which it is prevented from being removed from the second opening by the second stopper.

The application also provides for a process for transferring petri-dishes from and to a container that includes the petri-dishes in a stack in a sterile environment, the process comprising:

(a) moving the stack of petri-dishes and the first and second plugs in the axial direction to expose the outermost petri-dish at the first opening of the cartridge housing,

(b) removing the outermost petri-dish from the stack,

(c) introducing a petri-dish into the interior space of the cartridge housing through the second opening in the axial direction,

(d) repeating the steps (a) to (c) until the second plug is exposed at the first opening, and

(e) removing the second plug from the stack and introducing the second plug into the interior space of the cartridge housing through the second opening in the axial direction in the at least one orientation.

Preferably, the process for transferring petri-dishes from and to a container comprises: (a) moving the stack of petri-dishes and the first and second plugs in the axial direction to expose the first plug at the first opening of the cartridge housing,

(b) removing the first plug from the stack and introducing the first plug into the interior space of the cartridge housing through the second opening in the axial direction in the at least one orientation in which it is prevented from being removed from the first opening by the first stopper,

(c) moving the stack of petri-dishes and the first and second plugs in the axial direction to expose the outermost petri-dish at the first opening of the cartridge housing,

(d) removing the outermost petri-dish from the stack,

(e) introducing a petri-dish into the interior space of the cartridge housing through the second opening in the axial direction,

(f) repeating the steps (c) to (e) until the second plug is exposed at the first opening of the cartridge housing, and

(g) removing the second plug from the stack and introducing the second plug into the interior space of the cartridge housing through the second opening in the axial direction in the at least one orientation in which it is prevented from being removed from the second opening by the second stopper.

Preferably, the stack of petri-dishes and the first and second plugs are moved in the axial direction in the interior space of the cartridge housing by means of a lifter device reciprocatingly entering the cartridge housing through the second opening.

Brief description of the drawings

Preferred embodiments of the present container and process will now be described by reference to the attached exemplary schematic drawing, in which:

Figure 1 is a schematic representation of an embodiment of a container for accommodating a plurality of petri-dishes as defined herein in a cross section;

Figure 2 is a schematic representation of the container of Figure 1 with associated hardware for handling the petri-dishes;

Figure 3 is a perspective representation of an embodiment of the container for accommodating a plurality of petri-dishes from outside and in a cut-away view before and after use; Figure 4 is a perspective representation of another embodiment of the container for accommodating a plurality of petri-dishes from outside and in a cut-away view before and after use;

Figure 5 is a perspective representation of a variant of the container for accommodating a plurality of petri-dishes; and

Figures 6a to 6g are sequences of perspective representations of the container of Figure 4 to explain a process for handling the petri-dishes stored in the container.

Detailed description

The concept of the presently defined container and process will now be described by reference to the drawing. A first embodiment of a container for accommodating a plurality of petri-dishes as defined herein is shown in Figure 1 in a cross section and in Figure 2 which shows the container with associated hardware for handling the petri- dishes.

The container 1 for accommodating a plurality of petri-dishes PD, i.e. a batch, according to this embodiment comprises a hollow cylindrical or tubular cartridge housing 2 configured to receive the plurality of petri-dishes PD in a stack S aligned with an axial direction of the cartridge housing 2 in a cylindrical interior space 3 of the cartridge housing 2. The petri-dishes are placed one on top of the other in a horizontal orientation and the petri-dishes are aligned so that the outer peripheries are flush in the axial direction to form a fictive cylinder.

The interior space is dimensioned to provide a certain gap with respect to the outer peripheries of the petri-dishes such that the stack S of petri-dishes PD can be freely moved in the axial direction within the hollow interior space 3 from one end to the other end and vice versa. The outer shape of the cartridge housing 2 is not particularly critical and may be polygonal, oval, square, rectangular or irregular in a cross-section perpendicular to the axial direction.

The container 1 is shown in a vertical upright orientation which is preferred for use when handling the petri-dishes as described later. However, depending on the external hardware a horizontal or inclined orientation is possible as well. The vertical upright orientation and directional statements as "upper" or "lower" referred to in the description are therefore only used to illustrate the container but should not be construed as limiting in any way.

A first (upper) axial end 4 of the cartridge housing 2 has a first opening 5 dimensioned so that the petri-dishes PD can be sequentially/consecutively exposed from the cartridge housing 2 in consequence of moving the stack S in the axial direction. A second (lower) axial end 6 of the cartridge housing 2 has a second opening 7 dimensioned so that the petri-dishes PD can be sequentially/consecutively inserted into the interior space 3 of the cartridge housing 2 in the axial direction.

A first stopper 9 is provided at the first opening 5 and a second stopper 11 is provided at the second opening 7. The first and second stoppers 9,11 protrude radially into the first and second openings 5,7 to form a certain restriction of the free opening area and they are configured to nevertheless allow a petri-dish PD in a horizontal orientation as arranged in the stack S to freely pass into and out from the interior space 3 through the respective first and second opening 5,7 in the axial direction. As the petri-dishes are typically rotational symmetrical, the petri-dishes may pass the first and second stoppers in any rotational orientation. In a case where the petri-dishes are nonrelational symmetrical it is sufficient that they may pass the first and second stoppers in at least one rotational orientation.

The first and/or the second stopper 9,11 is/are integrally formed with the cartridge housing 2, is/are fixedly connected with the cartridge housing 2 (for example by welding, molding, gluing), or is/are removably provided at the cartridge housing 2. In the latter case they may be, for example, adhered and/or mechanically fixed by a threaded or bayonet-type releasable connection or by means of separate fasteners like hooks or clamps. In the latter cases the stoppers may also be formed of a different material from that of the cartridge housing. The first stopper may be formed based on a concept, structure and/or material that is different from that of the second stopper. In a non-illustrated example the one or both stoppers 9,11 may be formed from an elastic or resilient material, preferably in an annular form, that is capable of being elastically deformed upon application of a certain force to let the petri-dish PD and the plugs described further below pass the free opening area in the one direction (into or out from the container) while the restoration of the form due to the elasticity prevents passing of these elements in the opposite direction. The container 1 comprises a first plug 10a that is configured to be inserted into the interior space 3 of the cartridge housing 2 in the axial direction through the second opening 7 at the lower end 6 while passing the second stopper 11 in at least one horizontal rotational orientation. In an alternative embodiment that will be described later in connection with Figure 3 the first plug 10a may be pre-assembled and provided in the interior space 3 without the possibility of passing any one of the first and/or second stoppers unless the stopper(s) is/are removed from the cartridge housing 2.

In any case, the first plug 10a is configured to be moved in the axial direction within the interior space 3 together with the stack S of petri-dishes PD, and it is configured to be prevented by the first, i.e. upper stopper 9 from being removed from the interior space ) through the first opening 5 in at least one orientation. This means that the first plug 10a, when reaching the (upper) end position at the first end 4 during the sliding movement in the axial direction, engages with the first stopper 9 and the first plug 10a can thus serve as a closure or lid for the (upper) first opening 5.

In one embodiment the shape and size of the first plug 10a relative to the free area of the first stopper 9 is such that the first plug 10a when rotated around its center axis aligned with the axial direction of the stack into a defined rotational orientation may fit through the free area of the stopper 9 in order to be removed from the interior space 3 of the cartridge housing just as the petri-dishes but is prevented from passing the free area in another or any other rotational orientation. In another embodiment, for example the one shown in Figure 3, the first plug 10a may be formed so as to not be able to pass the (upper) stopper 9.

In a variant where a rotation of the first plug 10a is to be prevented at least along certain parts of the interior of the container during the sliding movement in the axial direction it is furthermore possible to provide one or more protrusions or guides 16 (see Figure 3) radially protruding from the inner peripheral surface 2a of the cartridge housing 2 and formed to engage with mating recesses or cut-outs 17 on the outer periphery of the first plug 10a for guiding its movement in the axial direction while preventing a rotation about the center axis aligned with the longitudinal direction. If a rotation of the first plug should be permitted at a distinct position in the axial direction, for example at its end position, the one or more guide(s) 16 may be interrupted (not shown). The arrangement of protrusion and mating recess can be reversed, i.e. the radial protrusion may be provided on the outer periphery of the plug and the mating recess may be recessed as a groove in the inner peripheral surface of the cartridge housing and a combination of the two alternatives on the same plug or on different plugs of a container is possible as well.

The container 1 moreover comprises a second plug 10b that is configured to be inserted into the interior space 3 of the cartridge housing 2 in the axial direction through the second (lower) opening 7 passing the second stopper 11 in at least one orientation but to be prevented from being removed through the second opening 7 in the opposite axial direction by the second stopper 11 in at least one orientation. This means that the second plug 10b can thus serve as a closure for the (lower) second opening 7. To prevent the second plug 10b from passing the second stopper 11 after insertion, it may be rotated around its center axis to a rotational orientation that prevents it from fitting through the opening area of the second stopper 11 or it may be formed to pass the stopper 11 when a certain pushing force in the axial direction is exceeded that elastically deforms the second plug and(/or the stopper that is sufficient to pass the stopper but prevents it from passing it in the opposite axial direction after restoration of its elastic deformation.

In any case, the second plug 10b is configured to be moved in the axial direction within the interior space 3 together with the stack S of petri-dishes PD, and it is configured to be removed from the interior space 3 through the first (upper) opening 5 passing the first stopper 9 in the at least one orientation.

As described above for the first plug 10a and if a rotation of the second plug 10b is to be prevented at least along certain parts of the interior of the container during the sliding movement in the axial direction, it is possible to provide one or more protrusions orguides (not shown) radially protruding from the inner peripheral surface of the cartridge housing and formed to engage with mating recesses or cut-outs on the outer periphery of the second plug 10b for guiding its movement in the axial direction while preventing a rotation about the center axis aligned with the longitudinal direction. Of course, the arrangement of protrusion and mating recess can be reversed as described for the first plug 10a. The guide(s) may be interrupted to permit a rotation of the second plug at a distinct position in the axial direction, for example at its end position at the lower end. Such protrusions or guides may be used for both plugs or different guides may be provided for each plug depending on the need. As described above the first and/or second plug 10a, 10b is/are formed so as to serve as a cover that can substantially or hermetically close the first and/or the second opening 5,7 in one orientation of the respective plug 10a, 10b resting against the first and/or second stopper 9,11. In order to improve the tightness of the closure a seal may be provided on the stopper(s) and/or the plug(s) 10a, 10b (not shown).

While the cartridge housing 2 is shown to be formed of a tubular element that is completely closed at its outer periphery, the wall may be opened by one or more opening/openings 12 for allowing air circulation between the outside environment and the interior space 3. Such a variant is shown in Figure 5 where plural elongated slots are formed so as to extend in parallel along the axial direction and distributed about the circumference. The form, dimension, orientation, arrangement and distribution of the openings are not relevant as long as the desired air circulation can be achieved. In a further variant that is not shown the openings means may be provided to selectively switch from a closed state of the openings to an open state and, if desired, back to the closed state. A one-way opening means may be realized in the form of a tape that adheres to the outer periphery and closes the openings and can be pulled or torn to be removed. A two-way opening means may be realized by designing the tape to be re- adherable or by providing a structure in the form of a second concentric cylinder or shell with openings, the second cylinder or shell being rotatable relative to the (first) cylinder to either align openings of both cylinders, or cover the openings of the one cylinder by solid wall sections of the other cylinder.

The container 1 may, in any embodiment or variant and independent from other features of the container, further comprise a film or cap respectively sealing the first and/or second opening 5,7 in a removable manner in particular in a state where the container is filled with a stack of pre-sterilized petri-dishes. In this way the sterility can be maintained during handling and transport until the container is ready for use on site in a closed sterile processing area or production isolator.

As shown in Figure 2 the container 1 as defined herein is intended to cooperate with associated hardware for handling the petri-dishes, i.e. for removing the petri-dishes from the stack in the container and putting them back into the container. Please note that a part of the hardware may be integrated in the container. This hardware is specifically designed to support a partly or fully automated process for handling the petri-dishes in connection with a microbial air sampler inside a closed sterile processing area or production isolator. The hardware comprises a lifter device 14 in the form of a plunger or piston and a oneway gate 8 that is arranged or configured to be arranged at the second (lower) opening 7 of the container 1 and that is configured to allow insertion of the petri-dishes PD into the interior space 3 in the axial direction and to prevent removal from the interior space 3 in the opposite axial direction. The one-way gate 8 thus temporarily supports the stack S as long as the second (lower) opening 7 is not securely closed by the second plug 10b because the petri-dishes PD as described are dimensioned so as to be not necessarily prevented by the second (lower) stopper 11 from passing the second (lower) opening 7 in the opposite axial direction. At the same time the one-way gate 8 allows insertion of the petri-dishes PD and of the first and second plugs 10a, 10b into the interior space 3 of the cartridge housing 2 in the axial direction, and it allows the introduction of the lifter device 14 into the second(lower) opening 7.

In one practical embodiment the one-way gate 8 comprises a plurality of retainers 20 that are distributed about the circumference of the second opening 7 and are configured to move between a first position where the retainers 20 partially block the second opening 7 to prevent removal of the petri-dishes PD from the interior space 3 in the opposite axial direction, and a second position where the retainers 20 allow insertion of the petri-dishes PD through the second opening 7 into the interior space 3 in the axial direction.

The retainers 20 may be formed by lever-like elements pivotally supported such that the lever-like elements protrude radially inward in a first pivoted position and are radially retracted in a second pivoted position. Preferably, the retainers 20 are biased, for example by a spring mechanism or by gravity or by a combination, into the first position and are movable against the bias into the second position.

It should be noted that the one-way gate 8 may be a part of the container 1 or may be a part of a separate external holder 13 configured to accommodate the container 1 in the vertical upright (or any other) orientation.

In the described variant the lifter device 14 is vertically movable and the container 1 remains in a fixed position. It is possible, however, to reverse the arrangement and to maintain the lifter device in a fixed position and move the container relative to the lifter device. The container 1 as defined herein that is ready to use is preferably equipped with a plurality of pre-sterilized petri-dishes PD in a parallel orientation in an aligned stack S received in the interior space 3 of the cartridge housing 2 in a sterile environment.

In a first variant of such ready-to-use entity the first and second plugs 10a, 10b are received in the interior space 3 of the cartridge housing 2 and are stacked below the bottom of the stack S of petri-dishes PD with the first plug 10a being arranged at the lower- or outermost position (see Figures 1 and 2 which show a schematic concept of this variant and Figure 3 which shows a more detailed example). In this entity the first and second ends or openings of the container are preferably sealed by disposable caps, seals or covers C to maintain the sterile state until the entity is used.

In a second variant of such ready-to-use entity the first plug 10a is arranged at the first end 4 of the cartridge housing 2 so as to be stacked above a top of the stack S of petri- dishes PD in an orientation in which it is not prevented from being removed from the first opening 5 by the first stopper 9, and the second plug 10b is received in the interior space 3 of the cartridge housing 2 stacked below a bottom of the stack s of petri-dishes PD in an orientation in which it is prevented from being removed from the second opening 7 by the second stopper 11 (see Figure 4). In this entity the first and second ends or openings of the container may be sufficiently sealed by the first and second plugs depending on the structure. However, in this case, too, the openings may be sealed by disposable caps, seals or covers (as shown in Figure 3 for the first variant) to maintain the sterile state until the entity is used.

In the following a process of using the container as described herein in connection with a microbial air sampler inside a closed sterile processing area or production isolator will be described in detail by reference to Figures 6a to 6g using the aforementioned second variant of Figure 4 and the external equipment of Figure 2 as an example. It is understood that the moving of the lifter device and the handling of the petri-dishes and plugs outside the container may be made in a fully automated process by means of suitable automation devices including a robotic arm without human intervention as the positional relations and the necessary kinematics are precisely defined. This does not exclude that the handling can be in part or fully performed by human interaction. Further, the introduction of the container as a ready-to-use entity into the closed sterile processing area or production isolator and onto a holder 13 with the one-way gate 8 (not shown in any of Figures 6a to 6g) and the removal of the container 1 out from the closed sterile processing area or production isolator after the batch of petri- dishes has been processed can be automated as well using, for example, a rapid transfer port device, or can be performed manually as is known in the art.

After any optional caps, seals or covers that are sealing the container are removed from the first and second ends of the container 1, the container 1 is placed on the holder 13 (Figure 6a). Then or before placement, if necessary, the first plug 10a at the upper end is rotated to a rotational orientation in which it can pass the first stopper 9.

The process for transferring petri-dishes PD from and to the second variant of the container 1 of Figure 4 comprises, inside the closed sterile processing area or production isolator, the following typical steps:

(a) moving/pushing the stack S of petri-dishes PD and the first and second plugs 10a, 10b at the upper and lower ends of the stack S in the axial upward direction by means of the plunger 14 entering the second (lower) opening 7 to expose the first plug 10a at the first (upper) opening 5 of the cartridge housing 2 (stage I of Figure 6b);

(b) removing the first plug 10a from the top of the stack S by suitable handling equipment (stage II of Figure 6b) and introducing the first plug 10a into the interior space 3 of the cartridge housing 2 through the second (lower) opening 7 in the axial direction in the at least one orientation in which it is prevented from being removed from the first opening 5 by the first stopper 9 (this step comprises the stage III of Figure 6b where the plunger is lowered and retracted from the second opening, the stack of petri-dishes slides downward by gravity until the second plug 10b at the lower end of the stack rests against the one-way gate, stage IV of Figure 6b where the first plug 10a is placed on the top of the plunger, stage I of Figure 6c where the plunger pushes the first plug upward through the one-way gate 8 and passed the second (lower) stopper 11);

(c) moving the stack S of petri-dishes PD and the first and second plugs 10a, 10b further upward in the axial direction to expose the upper- or outermost petri- dish PD at the first opening 5 of the cartridge housing 2 (stage II of Figure 6c);

(d) removing the upper- or outermost petri-dish PD from the stack S and transferring it to the point of use at the air sampler (stage III of Figure 6c);

(e) introducing a petri-dish PD into the interior space 3 of the cartridge housing 2 through the second (lower) opening 7 in the upward axial direction (this step comprises stage IV of Figure 6b where the plunger is lowered and retracted from the second opening, the stack of petri-dishes slides downward by gravity until the second plug 10b at the lower end of the stack rests against the one-way gate, stage I of Figure 6d where the used petri-dish is placed on the top of the plunger, stage II of Figure 6d where the plunger moves upward and pushes the first plug upward through the one-way gate 8 and passed the second (lower) stopper 11);

(f) repeating the steps (c) to (e) until the second plug 10b is exposed at the first (upper) opening 5 of the cartridge housing 2 (this step comprises all stages from, and including, stages II of Figure 6c to stage VI of Figure 6e, respectively to stage II of Figure 6f); and

(g) removing the second plug 10b from the stack S and introducing the second plug 10b into the interior space 3 of the cartridge housing 2 through the second (lower) opening 7 in the axial direction in the at least one orientation in which it is prevented from being removed from the second opening 7 by the second stopper 11 (this step comprises stages III of Figure 6f to II of Figure 6g).

Finally, the plunger is retracted from the second (lower) opening and the container 1, that is now closed at its upper and lower ends by the first and second plugs, respectively, and has the used petri-dishes arranged in the stack between the plugs in the interior space of the cartridge housing, is removed from the holder and transported out from the closed sterile processing area or production isolator for further processing (stages III and IV of Figure 6g).

While the preparatory and final handling is the same if the first variant of the container 1 of Figure 3 is used, the typical steps (a) to (g) of the process described before are somewhat modified and replaced by the following steps:

(a) moving the stack S of petri-dishes PD and the first and second plugs 10a, 10b in the axial direction to expose the upper- or outermost petri-dish PD at the first opening 5 of the cartridge housing 2;

(b) removing the upper- or outermost petri-dish PD from the stack S;

(c) introducing a petri-dish PD into the interior space 3 of the cartridge housing 2 through the second opening 7 in the axial direction;

(d) repeating the steps (a) to (c) until the second plug 10b is exposed at the first opening 5, and

(e) removing the second plug 10b from the stack S and introducing the second plug 10b into the interior space 3 of the cartridge housing 2 through the second opening 7 in the axial direction in the at least one orientation. It is understood that the operation of the plunger (which represents the lifter device that reciprocatingly enters the cartridge housing 2 through the second opening 7 in order to move the stack S of petri-dishes PD and the first and second plugs 10a, 10b are in the axial direction in the interior space 3 of the cartridge housing 2) and the handling of the petri-dishes and first and second plugs outside the container by a robotic device is the same as described above.

The container 1 may be overall disposable and designed for a single use. In this case the components may be made of a suitable plastics material. However, the container 1 and all or at least part of its components like the cartridge housing 2, the first and second stoppers 9,11 and the first and second plugs 10a, 10b may be designed for reuse and adapted to be sterilized as known in the art.