SUBSTRATE FOR TESTING SAMPLES AND SYSTEM COMPRISING THE SAME

Abstract

The invention relates to a substrate for testing samples, in particular cells or molecules, wherein the substrate comprises a fluid system comprising a sample chamber configured in the substrate for storing and testing samples and at least one liquid reservoir in fluid communication with the sample chamber, and wherein the substrate comprises a passive blocking element capable of assuming a closed position and an open position, wherein in the closed position a fluid exchange between the sample chamber and the liquid reservoir is blocked.

Claims

1. A substrate (1) for testing samples (24), in particular cells or molecules, wherein the substrate (1) comprises a fluid system (2) comprising a sample chamber (3) configured in the substrate (1) for storing and testing samples (24) and at least one liquid reservoir (4, 5) in fluid communication with the sample chamber (3); and wherein the substrate (1) comprises at least one passive blocking element (13, 15) that can assume a closed position and an open position, wherein in the blocking position a fluid exchange between the sample chamber (3) and the liquid container (4, 5) is blocked.

2. The substrate (1) according to claim 1, wherein the passive blocking element is configured in such a way that it assumes the closed position or the open position depending on the pressure conditions in the fluid system.

3. The substrate (1) according to claim 1, wherein no active components are arranged in the substrate (1), in particular no active valves and/or pumps.

4. The substrate (1) according to claim 1, wherein the liquid reservoir (4, 5) is lockable in such a way that it has no direct connection to the outside, in particular, is completely closed to the outside, and/or wherein the sample chamber (3) is lockable in such a way that it has no direct connection to the outside, in particular, is completely closed to the outside, in particular, wherein the entire fluid system (2) is lockable in such a way that it has no direct connection to the outside, in particular, is completely closed to the outside.

5. The substrate (1) according to claim 1, wherein the substrate (1) comprises at least two passive blocking elements (13, 15), in particular, wherein the substrate (1) is configured such that the blocking elements (13, 15) assume the closed position or the open position independently of one another.

6. The substrate (1) according to claim 1, wherein the fluid system (2) comprises a plurality of liquid reservoirs (4, 5) in fluid communication with the sample chamber (3) and the substrate (1) comprises a plurality of passive blocking elements (13, 15), wherein in the closed position of the blocking elements (13, 15), a liquid exchange between the sample chamber (3) and one of the liquid reservoirs (4, 5) is blocked and/or a liquid exchange between the liquid reservoirs (4, 5) is blocked, respectively; in particular wherein the substrate (1) is configured in such a way that the blocking elements (13, 15) assume the closed position or the open position independently of one another.

7. The substrate (1) according to claim 1, wherein the fluid system (2) comprises a first fluid channel (4b, 5b) that is part of or directly in fluid communication with the liquid reservoir (4, 5) and a second fluid channel (6, 7) that is directly in fluid communication with the sample chamber (3); wherein the first fluid channel (4b, 5b) is directly adjacent to the second fluid channel (6, 7) and the blocking element (13, 15) is arranged between the first fluid channel (4b, 5b) and the second fluid channel (6, 7); in particular, wherein the fluid system (2) comprises at least a first sample chamber (3-1) and a second sample chamber (3-2) and at least two second fluid channels (6-1, 6-2, 7-1, 7-2), wherein the first fluid channel (4b, 5b) is connected to the first sample chamber (3-1) via one of the second fluid channels (6-1, 7-1) and to the second sample chamber (3-2) via another of the second fluid channels (6-2, 7-2).

8. The substrate (1) according to claim 1, wherein the fluid system (2) comprises at least a first blocking element (13-1) and a second blocking element (13-2), at least a first liquid reservoir (4-1) and a second liquid reservoir (4-2), at least two first fluid channels (4b-1, 4b-2) and a second fluid channel (6) which is directly in fluid communication with the sample chamber (3), wherein one of the first fluid channels (4b-1) is part of or directly in fluid communication with the first liquid reservoir (4-1) and another of the first fluid channels (4b-2) is part of or directly in fluid communication with the second liquid reservoir (4-2); and wherein the first fluid channels (4b-1, 4b-2) are directly adjacent to the second fluid channel (6) and the first blocking element (13-1) is arranged between one of the first fluid channels (4b-1) and the second fluid channel (6) and the second blocking element (13-2) is arranged between the other of the first fluid channels (4b-2) and the second fluid channel (6); in particular, wherein the fluid system (2) comprises at least a first sample chamber (3-1) and a second sample chamber (3-2) and at least two second fluid channels (6-1, 6-2), wherein at least one of the first fluid channels (4b-1, 4b-2) is connected to the first sample chamber (3-1) via one of the second fluid channels (6-1) and to the second sample chamber (3-2) via another of the second fluid channels (6-2).

9. The substrate (1) according to claim 1, wherein the fluid system (2) comprises at least a first blocking element (13) and a second blocking element (15), at least a first liquid reservoir (4) and a second liquid reservoir (5), at least two first fluid channels (4b, 5b) and at least two second fluid channels (6, 7) which are directly in fluid communication with the sample chamber (3); wherein one of the first fluid channels (4b) is part of the first liquid reservoir (4) or is directly in fluid communication therewith and is directly adjacent to one of the second fluid channels (6), and the first blocking element (13) is arranged therebetween; wherein another of said first fluid channels (5b) is part of or directly in fluid communication with said second liquid reservoir (5) and is directly adjacent to another of said second fluid channels (7), and said second blocking element (15) is arranged therebetween; in particular wherein the first blocking element (13) has only one direction of passage from the first liquid reservoir (4) into the sample chamber (3) and the second blocking element (15) has only one direction of passage from the sample chamber (3) towards the second liquid reservoir (5), and/or in particular wherein the first blocking element (13) is arranged above the first fluid channel (4b) adjacent to the first blocking element (13) and below the second fluid channel (6) adjacent to the first blocking element (13) and/or wherein the second blocking element (15) is arranged below the first fluid channel (5b) adjacent to the second blocking element (15) and above the second fluid channel (7) adjacent to the second blocking element (15).

10. The substrate (1) according to claim 7, wherein the first fluid channel (4b, 5b) and the second fluid channel (6, 7), in a region in which the first fluid channel (4b, 5b) is directly adjacent to the second fluid channel (6, 7), are arranged overlapping each other in a top view of the substrate (1), and the first fluid channel (4b, 5b) is arranged above or below the second fluid channel (6, 7); in particular, wherein the substrate (1) has at least two first fluid channels (4b, 5b) and two second fluid channels (6, 7), wherein each one of the first fluid channels (4b, 5b) is adjacent to one of the second fluid channels (6, 7) each and wherein one of the first fluid channels (4b) is arranged below the second fluid channel (6) adjacent thereto and the other of the first fluid channels (5b) is arranged above the fluid channel (7) adjacent thereto.

11. The substrate (1) according to claim 1, wherein the substrate (1) has at least one connection (17, 18), wherein the substrate (1) is configured such that gas can enter, in particular be pumped, into the liquid reservoir (4, 5) via the connection (17, 18); in particular wherein the substrate (1) has at least a first connection (17) and a second connection (18), wherein the substrate (1) is configured in such a way that gas can enter, in particular be pumped, into one of the liquid reservoirs (4) via the first connection (17) and gas can enter, in particular be pumped, into another of the liquid reservoirs (5) via the second connection (18).

12. The substrate (1) according to claim 1, wherein the substrate (1) comprises a displacement member (36) comprising a chamber (36a) having no fluidic communication with the liquid reservoir (4, 5) and at least one connection (37); wherein the displacement member (36) is configured in such a way that pumping gas and/or liquid into the chamber (36a) increases the volume of the chamber (36a); and wherein the substrate (1) is formed and arranged in such a way that gas and/or liquid can be pumped into the chamber (36a) via the connection (37) and that the volume of the liquid reservoir (4, 5) is reduced when the volume of the chamber (36a) is increased by pumping gas and/or liquid into the chamber (36a).

13. A system (44) comprising the substrate (1) according to claim 1, wherein the system (1) comprises a pump system (53) adapted to be connected to the substrate (1), in particular to one or more of the connections (17, 18, 37) of the substrate, in particular comprising at least one pump (47, 52), and wherein the system optionally comprises a controller (54) for controlling the pump system (53).

14. A method of using the substrate (1) according to claim 1, comprising applying pressure to the fluid system (2), in particular by means of the pump system (53), in such a way that at least one of the blocking elements (13, 13-1, 13-2, 15) assumes an open position and liquid is transported from one of the liquid reservoirs (4, 5) into the sample chamber (3) and/or liquid is transported from the sample chamber (3) into one of the liquid reservoirs (4, 5), and optionally in such a way that at the same time at least one other of the blocking elements (13, 13-1, 13-2, 15) assumes an open position and/or another of the blocking elements (13, 13-1, 13-2, 15) assumes a closed position.

15. The method according to claim 14, wherein the application of pressure is performed in such a way that a first liquid, for example a flushing liquid or a buffer, is transported from a first liquid reservoir (4-1) into the sample chamber (3) and thereby a second liquid is displaced from the sample chamber (3), in that the second liquid is transported into a second liquid reservoir (5), and in that subsequently a third liquid is transported from a third liquid reservoir (4-2) into the sample chamber (3) and thereby the first liquid is displaced from the sample chamber (3), in particular in such a way that the first liquid is transported into the second liquid reservoir (5) or into a fourth liquid reservoir.

Description

[0115] Further features and advantages will be described below with reference to the exemplary figures, wherein

[0116] FIGS. 1a and 1b show a schematic not to scale top view and cross-section view of a substrate of a first embodiment;

[0117] FIGS. 2a to 2c show schematic, not to scale, cross-sectional views of a blocking element in the form of a check valve;

[0118] FIGS. 3a to 3c show schematic, not to scale, cross-sectional views of a substrate in the region of a liquid reservoir;

[0119] FIG. 4 shows a schematic not to scale cross-sectional view of a substrate of a second embodiment;

[0120] FIGS. 5a to 5c show schematic, not to scale, representations of partial areas of a substrate;

[0121] FIGS. 6a to 6c show schematic, not to scale, representations of sample chambers;

[0122] FIGS. 7a and 7b show schematic, not to scale, representations of possible configurations of the fluid system and blocking elements;

[0123] FIG. 8 shows a schematic not to scale representation of an embodiment of a system; and

[0124] FIGS. 9a to 9e show schematic not to scale representations of sample chambers.

[0125] In the following and in the figures the same reference numerals are used for the same or corresponding elements in the various embodiments unless otherwise specified. The sectional views below are each sections along the longitudinal axis of the substrate.

[0126] FIGS. 1a and 1b show a first embodiment of a substrate 1 for testing samples. The substrate comprises a fluid system 2.

[0127] The fluid system comprises a sample chamber 3 configured in the substrate and a first liquid reservoir 4 connected to the sample chamber and comprising a chamber 4a and a fluid channel 4b. Further, the fluid system comprises a second liquid reservoir 5 comprising a chamber 5a and a fluid channel 5b. In the present embodiment, the liquid reservoirs 4 and 5 are configured entirely in the substrate. However, this does not have to be the case. For example, optionally at least one of the chambers may not be configured in the substrate but may be arranged in a receiver in the substrate, such as a bag as described below.

[0128] The fluid system also comprise a fluid channel 6 that is in fluid communication with the sample chamber 3 and the liquid reservoir 4. Furthermore, the fluid system comprises a fluid channel 7 fluidically connecting the sample chamber 3 and the liquid reservoir 5.

[0129] The fluid channel 6 is fluidically directly adjacent to the first liquid reservoir 4, in this embodiment for example to the fluid channel 4b. The fluid channel 7 is directly adjacent to the second liquid reservoir 5, in this embodiment for example to the fluid channel 5b.

[0130] In the top view shown in FIG. 1 b, it is shown that the fluid channel 4b and the fluid channel 6 overlap each other in the area 9 where they are directly adjacent to each other, and that the fluid channel 5b and the fluid channel 7 overlap each other in the area 10 where they are directly adjacent to each other.

[0131] In the sectional view shown in FIG. 1a, the fluid channel 4b is shown to be located below the fluid channel 6 in the area 9 where the fluid channel 4b and the fluid channel 6 overlap. Furthermore, in the sectional view shown in FIG. 1a, the fluid channel 5b is arranged above the fluid channel 7 in region 10 where the fluid channel 5b and the fluid channel 7 overlap.

[0132] In the present example, the fluid channels 4b, 6 and 7 each run horizontally. The fluid channel 5b is angled and comprises two horizontally extending partial areas and a vertically extending partial area connecting the two horizontal partial areas. One of the horizontal partial areas is immediately adjacent to the fluid channel 7, and the other of the horizontal partial areas is immediately adjacent to the chamber 5a.

[0133] Just as an example, the fluid channel 4b, the fluid channel 7, and one of the horizontal partial areas of the fluid channel 5b, in particular the partial area of the fluid channel 5b immediately adjacent to the chamber 5a, are arranged in a first plane 11. The fluid channel 6 and the one other of the horizontal partial areas of the fluid channel 5b, in particular the portion of the fluid channel 5b immediately adjacent to the fluid channel 7, are arranged in a second plane 12. In this example, the first level is arranged below the second level.

[0134] The substrate further comprises a first passive blocking element 13 configured and arranged to block fluid exchange between the sample chamber and the first liquid reservoir 4. In particular, the first passive blocking element is arranged between the fluid channel 4b and the fluid channel 6 and is immediately adjacent to the fluid channel 4b and the fluid channel 6. The blocking element 13 is arranged in the area 9 where the fluid channel 4b and the fluid channel 6 overlap each other.

[0135] The first blocking element can be in the form of a check valve, for example in the form of an umbrella valve. The operation of such a check valve will be explained in more detail in connection with FIGS. 2a to 2c. As an alternative to an umbrella valve, a duckbill valve or other valve can be used. The blocking element 13 can, for example, have a passage direction 14. Alternatively, a blocking element can be used that has two passage directions.

[0136] The substrate further comprises a second passive blocking element 15 configured and arranged to block fluid exchange between the sample chamber and the second liquid reservoir 5. In particular, the second passive blocking element is arranged between the fluid channel 5b and the fluid channel 7 and is immediately adjacent to the fluid channel 5b and the fluid channel 7. The blocking element 15 is arranged in the area 10 where the fluid channel 5b and the fluid channel 7 overlap each other.

[0137] Also the second blocking element 15 can be in the form of a check valve, for example in the form of an umbrella valve. The blocking element can, for example, have a passage direction 16. Alternatively, a blocking element can be used that has two passage directions.

[0138] FIGS. 1a and 1b also show a first connection 17, here in the form of an opening. The substrate, in particular the first liquid reservoir 4, can be connected to a pump system via this connection. This pump system is not part of the substrate. The connection is arranged on the upper outer wall of chamber 4a, here formed as an opening in the upper outer wall. Alternatively, the connection can be provided on a side wall or the bottom of the chamber. Here, the upper outer wall is part of a removable lid 8 of the chamber 4a.

[0139] Also shown in FIGS. 1a and 1b is a second connection 18, here in the form of an opening. The substrate, in particular the second liquid reservoir 5, can be connected to a pump system via this connection. The connection is arranged on the upper outer wall of chamber 5a, here formed as an opening in the upper outer wall. Alternatively, the connection can be provided on a side wall or the bottom of the chamber. Here, the upper outer wall is part of a removable lid 8 of the chamber 5a.

[0140] For illustrative purposes, FIGS. 1a and 1b indicate the longitudinal axis 19a, the transverse axis 19b, and the vertical axis 19c of the substrate.

[0141] In the embodiment shown in FIGS. 1a and 1b, the substrate 1 is multi-part and comprises a structured bottom plate 20 and a structured cover plate 21.

[0142] In addition, FIGS. 1a and 1b show two openings 22 and 23 arranged immediately above the sample chamber. In the figures, the openings are shown in a closed state with a lid 22a and 23a, respectively. Prior to sealing, one of the openings 22 may be used to fill the sample chamber with the sample. In this regard, the other opening 23 may also be unsealed and serve to allow air to escape from the sample chamber during or after filling of the sample chamber. One or both of lids 22a and 23a may have connections for a compressed air system.

[0143] For illustrative purposes, FIGS. 1a and 1b show a sample 24, which may be arranged in the sample chamber during the intended use. FIGS. 1a and 1b show an example of the sample in the form of a plurality of cells 24a.

[0144] An observation region 25 for observing the samples in the intended use is also indicated in FIG. 1b. In FIGS. 1a and 1b, a transport direction 29 of the liquid through the fluid system provided in the intended use is also indicated with arrows.

[0145] In FIG. 1a, hoses 48 and 50 connected to the connections and a pump 47 are shown for better understanding, but are not part of the substrate.

[0146] Optionally, the entire substrate or only a portion of the substrate may be transparent, in particular formed from a transparent plastic material. In particular, the bottom of the sample chamber can be transparent. In particular, the substrate can be configured in such a way that the cells contained therein can be inspected microscopically.

[0147] When positive pressure is applied to the liquid reservoir 4 in a substrate shown as in FIGS. 1a and 1b, fluid is transported into the chamber through the fluid channel 4b and the fluid channel 6 and out of the chamber through the fluid channel 7 into the liquid reservoir 5. The locking elements 13 and 15 are arranged in such a way that this corresponds to the opening direction and, as a result of the application of the overpressure, the blocking elements assume the open position. On the other hand, if a negative pressure is applied to the chamber 4, the blocking element 13 assumes a blocking position and no liquid can be exchanged between the sample chamber and the liquid reservoir 4. For example, in the arrangement shown in FIGS. 1a and 1b, unused process liquid can be stored in the liquid reservoir 4 and passed through the sample chamber as needed and then fed to the liquid container 5. The liquid reservoir 5 can serve as a waste reservoir. If the substrate has a plurality of sample chambers and/or liquid is supplied to the sample chamber from a plurality of additional liquid reservoirs, the liquid reservoir 5 may also be configured for liquids from a plurality of the sample chambers and/or from a plurality of liquid reservoirs. Alternatively or additionally, the substrate may comprise at least one additional waste reservoir.

[0148] FIGS. 2a to 2c show an example of the operation of a blocking element in the form of a check valve, here using the example of an umbrella valve. For illustration purposes, in FIGS. 2a to 2c, the blocking element is arranged like the blocking element 13 in FIGS. 1a and 1b.

[0149] FIGS. 2a to 2c show that a horizontally arranged wall 26 is arranged between the fluid channel 4b and the fluid channel 6 in the area of the valve. The wall has one or more connecting holes 27 arranged around a central hole 28 below the umbrella 13a of the umbrella valve. The umbrella valve is fixed by means of the central bore, in particular by means of an anchoring element 13b of the umbrella valve, which is anchored in the central bore.

[0150] Depending on the pressure P1 applied to the fluid channel 4a and the pressure P2 applied to the fluid channel 6, the fluidic behavior of the check valve changes. In particular, the fluidic behavior of the check valve changes depending on the pressure difference between P1 and P2. When P1 and P2 are equal, the valve assumes a closed position, i.e. it is closed. If the pressure P2 is greater than P1, i.e. the pressure difference has a negative value, which is referred to as back pressure, this reliably keeps the valve in the closed position and thus supports the closing action of the valve. For example, this can be achieved by P2 being the ambient pressure and P1 being a negative pressure generated by a pump, for example. Alternatively, this can be achieved, for example, if P1 corresponds to the ambient pressure and P2 is a positive pressure generated by a pump, for example. If the pressure difference is below a threshold value, also known as opening pressure, the valve also assumes a closed position, i.e. it is closed. The valve in blocking position is shown in FIG. 2a. If the pressure difference is greater than or equal to the threshold value, the valve assumes an open position, i.e. it is open. The valve in open position is shown in FIG. 2a.

[0151] In the case of the umbrella valve, the umbrella 13a of the umbrella valve rests on the wall 26 in the closed position in such a way that no liquid is exchanged between the fluid channel 4a and the fluid channel 6. In particular, the bearing surface of the umbrella surrounds all the connection holes. In the open position, the umbrella is lifted from the support surface, allowing liquid to flow between the fluid channel 4a and the fluid channel 6. Due to the pressure difference required to open the umbrella valve, the liquid flows here primarily from the fluid channel 4a into the fluid channel 6.

[0152] FIG. 2c shows a top view, in which it can be seen in particular how the connection holes are arranged relative to the valve.

[0153] FIGS. 3a to 3c each show cross-sectional views of the substrate in the region of a liquid reservoir. A substrate according to the invention may be formed in the region of one, more or all of the liquid reservoirs as shown in these figures.

[0154] FIG. 3a shows a cross-sectional view of a substrate 1 in the region of a liquid reservoir 4a, which is configured essentially as shown in FIGS. 1a and 1b, Unlike FIGS. 1a and 1b, the bottom of the chamber may be configured to comprise one or more partial areas 30 that slope toward the fluid channel 4b. In other words, the bottom of the chamber may have slopes that slope toward the fluid channel. In particular, the liquid reservoir can have a shape of a funnel. If the substrate comprises a bottom plate and a cover plate, the inclined partial areas may be configured in particular in the cover plate, as shown in FIG. 3a.

[0155] FIG. 3a shows a cross-sectional view of a substrate 1 in the region of a liquid reservoir 4a, which is configured essentially as shown in FIGS. 1a and 1b. Unlike FIGS. 1a and 1b, the substrate has an adapter 31, here exemplarily a female Luer adapter. For example, a pump system not shown here can be connected to the adapter by means of a hose 32. In particular, a male Luer adapter 33 may be attached to the end of the tubing for connection to the female Luer adapter. The tubing and male Luer adapter are not part of the substrate and are shown here for illustrative purposes only. However, they can be part of a system according to the invention. Unlike in FIG. 3a, where the connection is arranged in a [!], here the connection in FIG. 3b is arranged in the cover plate of the substrate, which forms the upper outer wall of chamber 4a.

[0156] FIG. 3c shows cross-sectional views of a substrate 1 in the region of the chamber 4a of a liquid reservoir. Here, the chamber 4a is formed in the substrate and a displacement element 36 in the form of a bag is arranged in the chamber, which can be connected to a pump system via a connection 37 of the substrate or can form a chamber of a liquid reservoir of the fluid channel system. In the intended use, increasing the volume of the bag 36 can displace liquid contained in the chamber 4a from the chamber in the direction of the arrow 38. Optionally, liquid or gas located in the bag may be displaced from the bag by liquid pumped into chamber 4a.

[0157] Various states of the system are shown in the figure, namely a first state in which the bag 36 displaces little volume in the chamber 4a, and a second state in which the bag 36 is partially inflated and displaces enough volume in the chamber 4a to transport fluid from the chamber 4a in the direction of the arrow 38 into the fluid channel 4b. The bag may be configured so that it is slack when not pressurized. The bag may be configured in such a way that its volume can be increased by pressurization such that it fills substantially the entire chamber. The bag may have walls that are elastic, in particular such that expansion of the walls caused by filling with liquid and/or by inflation is reversible. The bag may be in the form of a balloon.

[0158] Chamber 4a is not connected to the pump system. This makes it easier to maintain sterility. In addition, transport of fluids independent of position relative to the gravity vector is easier.

[0159] As an alternative to the pouch being connectable to a pump via a connection of the substrate, the bag may form one of the chambers of a liquid reservoir of the fluid channel system and may be connected to a fluid channel. For example, transport of a liquid into the bag may thus cause transport of a liquid out of the chamber 4a. In particular, the bag can serve as a collection reservoir for used liquid.

[0160] As a variation of the arrangement shown in FIG. 3c not shown in the figures, the displacement element 36 described above may be arranged in a receiver in the substrate, and the chamber 4a of the liquid reservoir may be formed as a second bag. The second bag may be configured in such a way that when there is no liquid therein and no pressurization, it is slack. The second bag may have walls that are elastic, particularly in such a way that expansion of the walls caused by filling with liquid is reversible. The bag may be in the form of a balloon.

[0161] In the embodiment shown in FIG. 3c and its variations, an elastic material that is stretched during inflation may be used for the bag 36. The bag then generates a pressure that compresses any compressible medium such as air. In the event that one wishes to control the displaced volume in the chamber of the liquid reservoir on the basis of the quantity of medium pumped into the bag 36, it is purposeful to measure the pressure in the bag 36 continuously and to compensate the mass of gas to be transported to the respective pressure value accordingly. In this case, the ideal gas equation p V=n R T serves as the basis for calculation.

[0162] FIG. 4 shows a second embodiment of the substrate. For example, the substrate may be formed in principle as described above, but may comprise liquid reservoirs 4-1 and 4-2 instead of liquid reservoir 4. The liquid reservoir 4-2 may comprise a chamber 4a-2 and a fluid channel 4b-2, and may be connected to the fluid channel 6 via a blocking element 13-2. The liquid reservoir can be connected to a pump system via a connection 17-2. Alternatively, it may be connected only to the fluid channel and fluid transport may occur by displacement of the fluid from the chamber, for example as shown in FIG. 3c. Chambers 4a-1 and 4a-2 may be arranged at different heights, as shown here. In particular, one chamber may be arranged below the other chamber and may overlap it completely or partially in plan view. Alternatively, the chambers can be arranged on one level. The chambers can therefore be arranged next to each other. The liquid reservoirs 4-1 and 4-2, blocking elements 13-1 and 13-2, and connections 17-1 and 17-2 may each be formed, for example, as described above in connection with the liquid reservoir 4, the blocking element 13, and the connection 17.

[0163] The operation of the substrate is similar to that described above in connection with FIGS. 1a and 1b. A positive pressure can be applied to the liquid reservoirs 4-1 and 4-2, for example one after the other, for example first to the liquid reservoir 4-1 and then to the liquid reservoir 4-2, while in each case no positive pressure or a negative pressure is applied to the other liquid reservoir. As a result, liquid is first transported from the one liquid reservoir 4-1 into the sample chamber 7. If there is already liquid, for example a first process liquid, in the sample chamber, it will be displaced by the liquid from the liquid reservoir 4-1 and transported into the liquid reservoir 5. If positive pressure is then applied to the liquid reservoir 4-2, the liquid is transported from this liquid reservoir into the sample chamber. If liquid is still present there, it is also displaced and transported, for example, into the liquid reservoir 5. In this way, for example, process liquids can be replaced in the sample chamber. Preferably, then, the liquid in the liquid reservoir 4-1 is a buffer or flushing liquid and the fluid in the liquid reservoir 4-2 is a second process liquid.

[0164] FIG. 5a shows a portion of a substrate in which a plurality of fluid channels 6-1 and 6-2, here exemplarily two, are adjacent to the fluid channel 4b of the first liquid reservoir 4. For illustrative purposes only, a representation is chosen here in which the fluid channels 6-1 and 6-2 are not shown overlapping with the fluid channel 4b, but offset to the right, so that the passage directions and blocking directions of the blocking elements 13-1 and 13-2 can be seen more clearly. A blocking element 13-1 and 13-2 is arranged between each of the fluid channel 4b and the fluid channels 6-1 and 6-2, for example one of the blocking elements described above. The substrate comprises a plurality of sample chambers 3-1 and 3-2, for example two in this case, with fluid channel 6-1 opening into sample chamber 3-1 and fluid channel 6-2 opening into sample chamber 3-2.

[0165] The substrate further comprises two liquid reservoirs 5-1 and 5-2, each comprising a chamber 5a-1, 5a-2 and a channel 5b-1, 5b-2. The substrate further comprises a fluid channel 7-1 adjacent to the fluid channel 5b-1 of the liquid reservoir 5-1, having a blocking element 15-1 arranged therebetween, and a fluid channel 7-2 adjacent to the fluid channel 5b-2 of the liquid reservoir 5-2, with a blocking element 15-2 arranged therebetween.

[0166] The substrate is configured in such a way that the liquid reservoir 5-1 and liquid reservoir 5-2 can be pressurized independently of each other, for example, each via its own connection 18-1, 18-2.

[0167] Fluid channel 7-1 opens into sample chamber 3-1 and fluid channel 7-2 opens into sample chamber 3-2. The liquid reservoirs and sample chambers may each be configured and arranged as described hereinabove. The sample chambers can be arranged at the same height.

[0168] As an alternative to the variant shown in FIG. 5a, in which a plurality of sample chambers are connected to a common first fluid channel 4b and to separate second fluid channels 5b-1, 5b-2, a plurality of sample chambers may be connected to a common second fluid channel 5b and to separate first fluid channels and corresponding liquid reservoirs. The substrate can then be configured in such a way that these liquid reservoirs can be pressurized independently of each other.

[0169] Both alternatives allow selective fluid transport, with reduced number of channel structures.

[0170] Just as an example, the substrate may have an arrangement of chambers and fluid channels as shown in European patent application number 20160085.5, wherein a blocking element according to the invention may be arranged at one or more of the mouths of the channels or chambers shown therein. The blocking elements make it possible to protect the liquid in the cell culture areas described in said patent application from diffusion-induced mixing with other liquids over longer periods of time.

[0171] FIG. 5b shows a part of a substrate having a plurality of liquid reservoirs, each comprising a fluid channel 4b-1, 4b-2, and 4b-3. Each of the fluid channels is adjacent to fluid channel 6, with a blocking element 13 arranged therebetween. In the example shown here, for example, it is a valve as shown in FIGS. 2a to 2c, but other blocking elements can be used instead. The fluid channel 6 is fluidically connected to the sample chamber, for example as shown in FIGS. 1a and 1b.

[0172] In FIG. 5c, the substrate comprises a plurality of liquid reservoirs each comprising a fluid channel 4b-1 to 4b-4, wherein the fluid channels 4b-1 to 4b-4 are connected to the fluid channel 6 via a single blocking element 13. This is a particularly space-saving embodiment.

[0173] FIG. 6a shows an example of a part of a substrate, in particular the sample chamber 3. Openings 22 and 23 are arranged above the sample chamber, through which samples, for example cells, can be introduced into the sample chamber and/or through which air can escape before closing. The openings can each be closed with a plug 39, for example. The openings and plugs can be conical in shape, for example. Apart from this, the substrate can be formed, for example, as described above. In the present example, it is shown that a sample 24, in particular in the form of cells, is arranged in a partial area of the bottom of the sample chamber. In particular, the bottom may be covered with adherent cells in the intended use. The partial area of the bottom is arranged between the openings 22 and 23 and can be considered as an observation region. In particular, the bottom can be in the form of a cover glass through which the cells can be microscoped.

[0174] FIG. 6b shows an example of a part of a substrate, in particular the sample chamber 3, in a cross-sectional view. FIG. 6c shows the part of the substrate that is shown in FIG. 6b in a cross-sectional view in plan view. The sample chamber has a plurality of reservoirs 40a and 40b in the form of little pots, each tapering downward here. The little pots are bounded on the sides by walls 41. The sample chamber also comprises a fluid channel 42 adjacent the top of the little pots. The fluid channels 6 and 7 open into the fluid channel 42. Fluid can thus be transported, for example, successively through fluid channel 6, fluid channel 42 and fluid channel 7. The fluid channel 42 is configured and arranged in such a way that when liquid is transported through the fluid channel 42, the liquid flows along the top of the pots. When cells are arranged in the little pots in the intended use, the cells are superfused as a result. Apart from this, the substrate can be formed, for example, as described above.

[0175] First of all, the sample chamber can have the shape of a cuboid. Then the sample, for example cells, can be placed in the little pots and the sample chamber closed, for example with a cover glass. The cover glass can be fixed with double-sided adhesive tape, for example. The cells may optionally be introduced into the pots in the form of spheroids 43 or form spheroids in the little pots.

[0176] FIGS. 7a and 7b each show schematically in plan view an example of a substrate with six liquid reservoirs R1, R2, R3, R4, R5 and R6. Each of the reservoirs may be configured, for example, as described above in connection with liquid reservoir 4 and 5. Each of the liquid reservoirs is connected to the sample chamber by at least one fluidic connection via a blocking element. Each of the liquid reservoirs R1 and R6 is connected to the sample chamber by only one fluidic connection. The liquid reservoir R1 is connected to the sample chamber via the blocking element V1, and the liquid reservoir R6 is connected to the sample chamber via the blocking element V10. The liquid reservoir R2 has two fluidic connections to the sample chamber, one via the blocking element V2 and one via the blocking element V7, wherein the blocking elements V2 and V7 may be check valves, wherein one of the check valves may have a direction of flow toward the sample chamber and the other of the check valves may have a direction of flow out of the sample chamber. The liquid reservoir R3 has two fluidic connections to the sample chamber, one via the blocking element V3 and one via the blocking element V6, wherein the blocking elements V3 and V6 may be check valves, wherein one of the check valves may have a direction of flow toward the sample chamber and the other of the check valves may have a direction of flow out of the sample chamber. The liquid reservoir R4 has two fluidic connections to the sample chamber, one via the blocking element V5 and one via the blocking element V8, wherein the blocking elements V5 and V8 may be check valves, wherein one of the check valves may have a direction of flow toward the sample chamber and the other of the check valves may have a direction of flow out of the sample chamber. The liquid reservoir R5 has two fluidic connections to the sample chamber, one via the blocking element V4 and one via the blocking element V9, wherein the blocking elements V4 and V9 may be check valves, wherein one of the check valves may have a direction of flow toward the sample chamber and the other of the check valves may have a direction of flow out of the sample chamber.

[0177] The liquid reservoirs can be configured and arranged in such a way that the fluid channels do not cross each other. Alternatively or additionally, the liquid reservoirs can be formed and arranged such that the fluid channels all have the same length. Alternatively or additionally, the liquid reservoirs can be formed and arranged in such a way that the fluid channels all have the same length.

[0178] FIGS. 7a and 7b each differ in the direction of passage of the valves, one direction being indicated by dots and the other by crosses. The arrangement of the valves results in the flow directions in the intended use.

[0179] These flow directions are described below by way of example. When positive pressure is applied to liquid reservoir R1 and negative pressure is applied to reservoir R6 at the same time, liquid flows through valve V1 into the sample chamber and through valve V10 into liquid reservoir R6.

[0180] When positive pressure is applied to liquid reservoir R2 and negative pressure is applied to reservoir R3 at the same time, liquid flows through valve V2 into the sample chamber and through valve V6 into liquid reservoir R3.

[0181] When positive pressure is applied to liquid reservoir R3 and negative pressure is applied to reservoir R2 at the same time, liquid flows through valve V3 into the sample chamber and through valve V7 into liquid reservoir R2. This applies analogously to the R4 and R5 liquid reservoirs.

[0182] If the liquid reservoirs and the valves are configured and arranged as in FIG. 7a, the liquid flows through the sample chamber in the same direction during transport from R2 to R3 as during transport from R3 to R2. This applies analogously to the R4 and R5 liquid reservoirs. In addition, the liquid flows through the sample chamber in the same direction during transport from R2 to R3 as during transport from R4 to R5. In addition, the liquid flows through the sample chamber in the same direction during transport from R2 to R3 as during transport from R1 to R6.

[0183] If the liquid reservoirs and the valves are configured and arranged as in FIG. 7b, the liquid flows through the sample chamber in the same direction during transport from R2 to R3 as during transport from R3 to R2. This applies analogously also to the R4 and R5 liquid reservoirs. Unlike the arrangement in FIG. 7a, however, the liquid flows through the sample chamber in the opposite direction during transport from R2 to R3 than during transport from R4 to R5.

[0184] FIG. 8 shows an example of a system 44 according to the invention with a substrate 1 as described in connection with FIG. 4. Alternatively, the system may comprise another of the substrates described above, for example as described in connection with FIG. 1, or another substrate according to the invention.

[0185] In this embodiment, the system comprises valves 45 and 46 and a pump 47 having a negative pressure outlet 47a and a positive pressure outlet 47b, each of which is connected to one or both of the valves 45 and 46 in the intended use. The system further comprises hoses 48 and 49, each of which is connected to one of valves 45 and 46 and to one of connections 17-1 and 17-2 of the substrate in the intended use. A tube 50 is connected to the connection 18 of the substrate. This hose can also optionally be connected to the pump 47 via a valve 51.

[0186] The system may comprise a controller 54 configured to control one or more of the valves and/or one or more of the pumps.

[0187] FIG. 9a shows a schematic representation of a valve that can be used as valve 45, valve 46 and/or valve 51. This is a 3/2-way valve. For example, a first connection of the valve may be connected to the overpressure outlet 47b of the pump and a second connection may be connected to the substrate. A third connection of the valve can optionally be connected to the vacuum outlet 47a of the pump. Alternatively, the third connection can be connected to ambient air or to another pump. The third connection, when connected to a pump, can be used to apply a vacuum to the respective liquid reservoir during operation. This allows the locking effect to occur on the blocking element.

[0188] FIG. 9b shows how the valve circuit may look when each of the valves 45, 46 and 51 is connected via two of its connections to the pump 47, more specifically to the negative pressure outlet 47a and the positive pressure outlet 47b. FIG. 9c shows how the valve circuit may look when each of the valves has one of its connections connected to a pump 52, for example for generating negative pressure, and another of its connections connected respectively to another pump 47-1, 47-2 and 47-3, for example for generating positive pressure for transport. This has the advantage that the positive pressure used to drive the fluid in the substrate can be provided independently for each of the liquid reservoirs, but the negative pressure that assists in sealing the blocking element can be easily provided by a common pump.

[0189] FIG. 9d shows how the valve circuit may look when each of the valves 45, 46 and 51 has one of its ports connected to the pump 47 and another of its connections connected to the further pump 52, wherein the pump 47 may be provided to provide the positive pressure and the pump 52 may be provided to provide the negative pressure.

[0190] Alternatively or additionally, at least one of the liquid reservoirs 4 can be connected directly to a pump 47 via a hose 48, i.e. without an intermediate valve, as shown in simplified form in FIG. 9e.

[0191] Pumps 47, 47-1, 47-2, 47-3 and/or 52 may each be in the form of a piston pump, peristaltic pump, c or screw pump. Especially for the pump provided for applying the overpressure, it is advantageous if the pump is configured in such a way that controllable volumes can be transported with it.

[0192] All pumps connected to the substrate and, if applicable, valves and hoses together form the pump system 53.

[0193] With regard to the function of the system, it should be noted that depending on the locking elements used, certain designs and modes of operation may be more advantageous than others. For example, in a duckbill valve, it is advantageous to apply back pressure to close the valve safely.

[0194] A method according to the invention comprises applying pressure to the fluid system 2 of one of the substrates 1 described above, for example by means of one of the systems 44 described above, more precisely by means of one of the pump systems 53 described above. In particular, the pressure can be applied so that the blocking element 13 or one of the blocking elements 13-1 and 13-2 assumes a let-through position, i.e. is open, and liquid is transported from the liquid reservoir 4 or one of the liquid reservoirs 4-1 and 4-2 into the sample chamber 3. The pressure can optionally be applied in such a way that, in particular at the same time, the blocking element 15 also assumes an open position and liquid is transported from the sample chamber 3 into the liquid reservoir 5. For example, a liquid already in the sample chamber may be displaced by the liquid from the liquid reservoir 4, 4-1 or 4-2 and transported into the liquid reservoir 5.

[0195] Optionally, if the substrate comprises, for example, at least three liquid reservoirs 4-1, 4-2, and 5, liquid may first be transported from one of the liquid reservoirs 4-1 into the sample chamber as described above, in particular by displacing a liquid already in the sample chamber into the liquid reservoir 5, and subsequently, liquid from the other of the liquid reservoirs 4-2 can be transported into the sample chamber and displace the liquid located in the sample chamber so that it is transported, for example, into the liquid reservoir 5 or another liquid reservoir, in particular into the liquid reservoir 4-1. Thus, a liquid exchange takes place in the sample chamber. In particular, the fluid initially in the sample chamber may be a first process fluid, the fluid supplied from the liquid reservoir 4-1 may be a purge fluid or buffer fluid, and the fluid supplied from the liquid reservoir 4-2 may be a second process liquid. This can ensure that first and second process liquids are not in the sample chamber at the same time. The exchange of process liquids is thus carried out in a more reliable manner.

[0196] While the liquid or liquids are in the sample chamber or being transported through the sample chamber, a sample may be in the sample chamber and optionally an examination of the sample, such as a microscopic inspection through the bottom of the sample chamber, may be performed.

[0197] The method may comprise, prior to the steps described above, introducing a sample, in particular directly through the openings 22 or 23, into the sample chamber and/or introducing the liquid or liquids into the liquid reservoirs and/or into the sample chamber. The method may comprise, after the sample and optionally a liquid have been introduced into the sample chamber, closing the sample chamber to the outside, for example by means of a lid 22a, 23a or a plug 39. Alternatively or additionally, the method may comprise, optionally after filling liquid into the respective liquid reservoir, closing the liquid reservoirs so that they are only open to the outside via the connections. The method may also comprise connecting to the connections the pump system.

[0198] The method may comprise not introducing any more liquid into the sample chamber after the sample chamber has been sealed, in particular at least until the liquid filled into the liquid reservoir 4 or 4-1 or 4-2 prior to sealing has been transported from the liquid reservoir 4 or one or both of the liquid reservoirs 4-1 and 4-2 into the sample chamber. In particular, the method may comprise not introducing fluid into the substrate after the sample chamber has been sealed until fluid has been transported into the sample chamber from all liquid reservoirs into which fluid was introduced prior to sealing.

[0199] It will be understood that features specified in the above described embodiments are not restricted to these special combinations and are also possible in any other combinations.