Microfluidic Treatment Apparatus and Method for Operating a Microfluidic Treatment Apparatus

Abstract

A microfluidic treatment apparatus has a microfluidic channel system having a filtering branch, a pumping branch connected in parallel with the filtering branch, and a filter chamber arranged in the filtering branch and configured to accommodate a filter element. The filtering branch is coupled to a channel inlet via a first channel-crossover element and to a channel outlet via a second channel-crossover element, and the filter chamber can be isolated from the rest of the channel system by at least two filter valves. A pumping device is arranged in the pumping branch, is configured to produce fluid flow in the channel system, and includes at least one pumping valve and at least one pumping chamber. The pumping branch is coupled to the channel inlet via a connection of the first channel-crossover element and to the channel outlet via a connection of the second channel-crossover element

Claims

1. A microfluidic treatment apparatus for treating a sample liquid, the microfluidic treatment apparatus comprising: at least one microfluidic channel system having at least one filtering branch and a pumping branch connected in parallel with the filtering branch; at least one filter chamber arranged in the filtering branch and is configured to accommodate a filter element; a first channel-crossover element configured to fluidically couple the filtering branch to a channel inlet; a second channel-crossover element configured to fluidically couple the filtering branch to a channel outlet; at least two filter valves configured to fluidically isolate the filter chamber from the rest of the channel system ; and a pumping device arranged in the pumping branch and configured to produce a fluidic flow in the channel system, the pumping device comprising at least one pumping valve and/or at least one pumping chamber, wherein the pumping branch is configured to be coupled fluidically to the channel inlet via a first connection of the first channel-crossover element which is different from a second connection of the first channel-crossover element for the filtering branch, and the pumping branch is configured to be coupled fluidically to the channel outlet via a first connection of the second channel-crossover element which is different from a second connection of the second channel-crossover element for the filtering branch.

2. The treatment apparatus according to claim 1, wherein the at least one pumping chamber includes at least two first pumping chambers arranged or connected in a row adjacent to one another.

3. The treatment apparatus according to claim 2, wherein the at least one pumping chamber further includes a second pumping chamber configured to be separated from the at least two first pumping chambers by at least one pumping valve.

4. The treatment apparatus according to claim 3, wherein each of the at least two first pumping chambers and the second pumping chamber have a volume that is substantially the same size.

5. The treatment apparatus according to claim 2, wherein at least two of the at least two first pumping chambers are configured to be temperature-controlled independently of one another.

6. The treatment apparatus according to claim 1, further comprising: a channel system expansion module configured to be fluidically coupled to the pumping branch the channel system expansion module comprising at least one upstream arrangement chamber configured for upstream arrangement of reagents and/or at least one evaluation chamber having evaluation cavities configured for evaluating sample constituents of a sample liquid.

7. The treatment apparatus according to claim 6, wherein: the upstream arrangement chamber configured to be fluidically coupled to the pumping branch by a channel connecting element that be is closed with an upstream arrangement valve; and the evaluation chamber is configured to be fluidically coupled to the pumping branch by a further channel connecting element that is closed with an evaluation valve.

8. The treatment apparatus (490) according to claim 1, wherein the the at least one pumping chamber comprises a single pumping chamber and the at least one pumping valve comprises at least three pumping valves.

9. The treatment apparatus according to claim 1, wherein an inlet valve is arranged between the channel inlet and the first channel-crossover element, and/or an outlet valve is arranged between the channel outlet and the second channel-crossover element.

10. A method for operating a microfluidic treatment apparatus having (i) at least one microfluidic channel system having at least one filtering branch and a pumping branch connected in parallel with the filtering branch, (ii) at least one filter chamber arranged in the filtering branch and configured to accommodate a filter element, (iii) a first channel-crossover element configured to fluidically couple the filtering branch to a channel inlet, (iv) a second channel-crossover element configured to fluidically couple the filtering branch to a channel outlet, (v) at least two filter valves configured to fluidically isolate the filter chamber from the rest of the channel system, and (vi) a pumping device arranged in the pumping branch and configured to produce a fluidic flow in the channel system, the pumping device comprising at least one pumping valve and/or at least one pumping chamber, the pumping branch configured to be coupled fluidically to the channel inlet via a first connection of the first channel-crossover element which is different from a second connection of the first channel-crossover element for the filtering branch, and the pumping branch configured to be coupled fluidically to the channel outlet via a first connection of the second channel-crossover element which is different from a second connection of the second channel-crossover element for the filtering branch the method comprising: introducing a sample liquid into the microfluidic treatment apparatus; extracting sample constituents present in the sample liquid through a filter element; and eluting sample constituents from the filter element.

11. The method according to claim 10, further comprising: lysing the sample liquid following the introduction of the sample liquid and before the extraction of the sample constituents; and/or washing the filter element and the filter chamber following the extraction of the sample constituents and before the elution of the sample constituents.

12. The method according to claim 10, further comprising one or more of the following: providing a reaction liquid by dissolving a reagent using the sample constituents following the elution of the sample constituents; carrying out an amplification reaction; aliquoting the reaction liquid; carrying out a detection reaction; and evaluating the reaction result.

13. A control unit configured to execute program instructions stored in a memory to carry out and/or actuate method according to claim 10 in corresponding units .

14. A computer program configured to carry out and/or actuate the method according to claim 10.

15. A non-transitory machine-readable storage medium on which the computer program according to claim 14 is stored.

16. The treatment apparatus according to claim 1, wherein the first and second channel-crossover elements are T-shaped.

17. The treatment apparatus according to claim 2, wherein the at least two pumping chambers includes three pumping chambers arranged or connected in series in the row.

Description

[0035] Embodiment examples of the approach presented herein are illustrated in the drawings and explained in further detail in the following description. The following are shown:

[0036] FIG. 1 a schematic representation of an embodiment example of a treatment apparatus;

[0037] FIG. 2 a schematic plan view of an embodiment example of a treatment apparatus;

[0038] FIG. 3 a schematic representation of an embodiment example of a treatment apparatus having a channel system expansion module;

[0039] FIG. 4 a schematic plan view of an embodiment example of a treatment apparatus having a channel system expansion module;

[0040] FIG. 5A a flow chart of an embodiment example of a method for operating a microfluidic treatment apparatus;

[0041] FIG. 5B a block diagram of a control unit for operating a microfluidic treatment apparatus according to a variant presented herein;

[0042] FIG. 6 a flowchart of an embodiment example of a method for operating a microfluidic treatment apparatus, with an additional step of lysing and an additional step of washing; and

[0043] FIG. 7 a flowchart of an embodiment example of a method for operating a microfluidic treatment apparatus having a channel system expansion module.

[0044] In the following description of favorable embodiment examples of the present invention, identical or similar reference numbers are used for the elements shown in the various figures and acting similarly, wherein a repeated description of these elements is dispensed with. If an embodiment example encompasses an “and/or” conjunction between a first feature and a second feature, this is to be read such that the embodiment example according to one embodiment example has both the first feature and the second feature and according to a further embodiment example has either only the first feature or only the second feature.

[0045] FIG. 1 shows a schematic representation of an embodiment example of a treatment apparatus 100. In this embodiment example, the treatment apparatus 100 is configured with lateral dimensions of 45 × 25 mm.sup.2. The treatment apparatus 100 in this embodiment example has a microfluidic channel system 105 for accommodating a sample liquid, that is to say a liquid having constituents of a sample. The cross-sectional area of the channel system 105 in this embodiment example is 0.4 × 0.6 mm.sup.2. In a further embodiment example, the channel system is formed with a cross-sectional area of 0.8 × 0.8 mm.sup.2. In this embodiment example, the sample liquid is introduced into the treatment apparatus 100 via a channel inlet 110, wherein the channel inlet 110 forms a connection to a microfluidic network, not shown in this figure. The channel inlet 110 can be separated from the remaining areas of the treatment apparatus 100 by means of an inlet valve 115. In this embodiment example, the inlet valve 115 is arranged between the channel inlet 110 and a first channel-crossover element 120, wherein the first channel-crossover element 120 preferably has a T-shape. While the channel inlet 110 is fluidically coupled to a port of the first channel-crossover element 120 via the isolating valve 115, another port of the first channel-crossover element 120 is fluidically coupled to a filtering branch 125 of the treatment apparatus 100. The filtering branch 125 has a filter chamber 130 in which, in this embodiment example, a filter element 135 is arranged, wherein the filter chamber 130 can be used for extracting sample constituents, which can also be referred to as constituents of a sample. A first filter valve 140a is arranged between the filter chamber 130 and the first channel-crossover element 125. Additionally, a second filter valve 140b is arranged between the filter chamber 130 and a second channel-crossover element 145. By means of the first filter valve 140a and the second filter valve 140b, the filter chamber 130 is separable from the remaining regions of the treatment apparatus 100. In other words, two filter valves 140a, 140b, which can also be referred to as microfluidic switching valves, are arranged on the microfluidic channel in as close proximity to the filter chamber 130 as possible on either side of the filter chamber 130, such that a closing of the two filter valves 140a, 140b separates the filter chamber 130 from the channel. In this embodiment example, the filter valves 140a, 140b have a particularly low volume so as to minimize the volume around the filter chamber 130. The filter valves 140a, 140b are merely aligned by way of example, so that they can be actuated together via exactly one pneumatic control channel.

[0046] Accordingly, the treatment apparatus 100 is characterized by a particularly advantageous arrangement and configuration of the microfluidic elements for a filter-based purification of a sample liquid, in particular by implementing an in particular loop-shaped microfluidic channel system 105, which contains a filter chamber 130 having a filter element 135, wherein the filter chamber 130 can be liquid-tightly separated from the remaining portion of the microfluidic channel system 105 by two microfluidic filter valves 140a, 140b. The two microfluidic filter valves 140a, 140b are in particular actuated together in order to achieve a particularly simple and compactly viable pneumatic control. The treatment apparatus 100 also has two preferably T-shaped channel-crossover elements 120, 145, which are arranged in the as immediate as possible vicinity of the two filter valves 140a, 140b surrounding the filter chamber 130, which can also be referred to as isolating valves, and form exactly two microfluidic bonds to the microfluidic channel system 105, such that, particularly when closing the isolating valves 140a surrounding the filter chamber 130, 140b, a flushing of the remaining part of the microfluidic channel system 105 via the connections is enabled.

[0047] With the second filter valve 140b open, the filter chamber 130 is fluidically coupled to a channel outlet 150 connected to a further port of the second channel-crossover element 145 via a port of the second channel element 145. In this embodiment example, the channel outlet 150 forms a link to a collection chamber not shown in the figure, wherein the channel outlet 150 can be used for dispensing the sample liquid after the extraction of constituents through the filter element 135. In doing so, the channel outlet 150 is separable from the remaining regions of the treatment apparatus 100 while congruent with the channel inlet 110 with an outlet valve 152. The first channel-crossover element 120 and the second channel-crossover element 145, both of which can also be referred to as channel-crossovers, accordingly enclose the filter chamber 130 and the two filter valves 140a, 140b arranged about the filter chamber 130, which can also be referred to as switching valves. In this manner, the result is an as low as possible volume of the filtering branch 125, thereby enabling a particularly efficient microfluidic processing, in particular in connection with the purification of a sample liquid.

[0048] A pumping branch 155 is connected to the filtering branch 125 in parallel with a pumping device 157, wherein the pumping branch 155 is fluidically coupled to the channel inlet 110 via a port of the first channel-crossover element 120 other than the filtering branch 125 and fluidically coupled to the channel outlet 150 via a port of the second channel-crossover element 145 other than the filtering branch 125. In this embodiment example, the filtering branch 125 and the pumping branch 155 form a loop-like, closable system via the connection through the channel system 105. In this embodiment, on the one hand, the pumping branch 155 has at least two, here exactly three pumping chambers 160a, 160b, 160c, which are directly adjacent to one another. The pumping chambers 160a, 160b, 160c in this embodiment example are arranged in series along the microfluidic channel system 105 and are thus connected in series and have nearly the same volume. By way of example only, they are fluidically separable from the remaining regions of the treatment apparatus 100 via two microfluidic pumping valves 165a, 165b surrounding the three pumping chambers 160a, 160b, 160c.

[0049] The row-shaped arrangement of the pumping chambers 160a, 160b, 160c and the pumping valves 165a, 165b on the loop-like microfluidic channel system 105, which can be used for conveying liquids through the filter chamber 130 and within the microfluidic channel system 105, allow for a peristaltic pumping operation. In this embodiment example, the pumping chambers 160a, 160b, 160c are further individually, that is, substantially independently of one another, temperature-controlled. In this manner, the three pumping chambers 160a, 160b, 160c can be used in addition to the controlled accommodation of sample liquid and the generation of a microfluidic flow in the channel system 105, in particular in the context of a purification of a sample liquid using the filter chamber 130 with the filter element 135 for carrying out, for example, a polymerase chain reaction. Following a purification of the sample liquid, the pumping chambers 160a, 160b, 160c thus also allow for an amplification of purified sample material in the treatment apparatus 100.

[0050] On the other hand, this embodiment has a further pumping chamber 170, wherein each of the pumping chambers 160a, 160b, 160c and the further pumping chamber 170 connected in series have a substantially equal volume, so that a total of four similar pumping chambers 160a, 160b, 160c, 170 are present. In this manner, a particularly flexible processing of liquid volumes is possible, which substantially correspond to the displacement volume of up to two of the pumping chambers 160a, 160b, 160c, 170, such that a performance of various steps of a test sequence within the treatment apparatus 100 is advantageously achievable. In this embodiment example, the further pumping chamber 170 can also be separated from the remaining regions of the treatment apparatus 100 by two further pumping valves 175a, 175b. In this respect, both the pumping valves 165a, 165b and the further pumping valves 175a, 175b are designed for use as peristaltic pumping valves in addition to the function of separation, and therefore have a greater displacement volume than the first filter valve 140a and the second filter valve 140b, which are configured so as to disconnect the filter chamber 130 from the remaining regions of the treatment apparatus 100.

[0051] FIG. 2 shows a schematic plan view of an embodiment example of a treatment apparatus 100. This can be the treatment apparatus described in FIG. 1.

[0052] In this embodiment example, the treatment apparatus 100 is based on a flexible, microstructured polymer membrane, which has been in particular partially welded to two microstructured polymer components by laser welding, which can also be referred to as laser transmission welding. In the rigid polymeric components, in particular, there are liquid-conducting recesses that realize the microfluidic passages of the channel system 105, the pumping chambers 160a, 160b, 160c, the further pumping chamber 170, the pumping valves 165a, 165b, the further pumping valves 175a, 175b, the filter valves 140a, 140b, the inlet valve 115, and the outlet valve 152. Further, at least one of the components has in particular pneumatic channels 210 which are used for controlling the active microfluidic elements, in particular the pumping chambers and the valves. The controlling of the microfluidic elements in this embodiment example is accomplished by a pressure-based locally defined deflection of the elastic membrane into the recesses of the polymeric components forming the valves and pumping chambers. At least two pressure levels are used for controlling the microfluidic elements. In particular, the pressure levels are controlled and provided by an external processing unit having a pneumatic interface 205 to the treatment apparatus 100. By way of example only, the interface 205 in this figure is arranged on the left edge of the figure. The pneumatic channels 210 used in order to control the microfluidic elements are shown in red in this figure. The microfluidic channels of the channel system 105 and the filter chamber 130 are shown in blue, and the pneumatically controllable microfluidic elements are visualized in red like the pneumatic channels 210.

[0053] FIG. 3 illustrates a schematic representation of an embodiment example of a treatment apparatus 100 having a channel system expansion module 300. This can be the treatment apparatus described in the previous figures.

[0054] In this embodiment, the pumping chambers 160a, 160b, 160c arranged in a row can be independently temperature-controlled by means of a temperature-control device, not shown. Merely by way of example, the first of the three pumping chambers 160a is brought to a temperature of 95° C., the second pumping chamber 160b is brought to a temperature of 70° C., and the third of the three pumping chambers 160c is brought to a temperature of 60° C. In this manner, carrying out a polymerase chain reaction within a volume of liquid pumped back and forth periodically between the three pumping chambers 160a, 160b, 160c is enabled. In this embodiment example, the series of pumping chambers 160a, 160b, 160c can be separated from the microfluidic channel system 105 by two microfluidic pumping valves 165a, 165b. In this manner, a particularly efficient back-and-forth pumping and temperature-control of the liquid plug in the three pumping chambers 160a, 160b, 160c are possible, wherein liquid losses are prevented by the separation of the unit from three pumping chambers 160a, 160b, 160c by means of the microfluidic pumping valves 165a, 165b, and the liquid chambers 160a, 160b, 160c adj acent to the pumping are minimized with the dead volumes of the thermal and microfluidic processing of the liquid volume.

[0055] In this embodiment example, the pumping branch 155 is fluidically coupled to an upstream arrangement chamber 310 via an additional preferably T-shaped channel-crossover element 305. By way of example only, the upstream arrangement chamber 310 is used in order to arrange freeze-dried reagents upstream. An upstream arrangement valve 320 is arranged between the additional channel-crossover element 305 and the upstream arrangement chamber 310 at a channel connecting element 315, wherein the upstream arrangement valve 320 is configured so as to separate the upstream arrangement chamber 310 from the pumping branch 155. Thus, in this embodiment example, the channel connecting element 315 establishes a connection between the pumping branch 155 and the microfluidic upstream arrangement chamber 310 that can be closed with the upstream arrangement valve 320, which upstream arrangement chamber contains at least one upstream reagent 318, in particular a so-called bead, which can also be referred to as a lyophilisate and which is suitable for the provision of a reaction liquid using an eluate, that is to say the liquid which is obtained from a purification of the sample liquid using the treatment apparatus 100 and the filter element 135 described in FIG. 1. In other words, a reaction liquid, which can also be referred to as a reaction mix, is provided by dissolving a bead in the microfluidic upstream arrangement chamber 310 by means of the eluate previously obtained from a purification. The upstream arrangement chamber 310 is, merely by way of example, pneumatically actuatable and thus comparable to the remaining pumping chambers 160a, 160b, 160c so as to also provide a pumping action with the upstream arrangement chamber 310.

[0056] In this embodiment example, the microfluidic channel system 105 between the additional channel-crossover element 305 and the further pumping valve 175a has a further preferably T-shaped channel-crossover element 325 having a further channel connecting element 327 via which the pumping branch 155 is fluidically coupled to an evaluation chamber 330. The further channel connection element 327 can be closed with an evaluation valve 335. The evaluation chamber 330, which can also be referred to as an array chamber, in this embodiment example has a chip having an array of evaluation cavities 345, which can also be referred to as microcavities. Only exemplary target-specific reagents are arranged upstream in the evaluation cavities 345, which allow a detection of different targets in the liquid by geometric multiplexing. In this manner, a sample can be investigated for a variety of different features using the channel system expansion module 300. The microfluidic valves 347a, 347b, which are in particular intended for microfluidic processing of the evaluation chamber 330 by means of peristaltic pumps, have, merely by way of example, a displacement volume designed for this purpose. In this embodiment example, the displacement volume of the microfluidic valves 347a, 347b exceeds the volume of the pumping valves 165a, 165b which are used for a peristaltic pump in the pumping branch 155. In this manner, a higher flow rate can be generated with the valves 347a, 347b, whereas the pumping valves 165a, 165b have a smaller space requirement and therefore allow as compact a realization of the apparatus as possible. Further, this embodiment example additionally comprises access to a further upstream arrangement chamber 350, which can also be referred to as a bead chamber, in which there is a further freeze-dried reagent 358, which can be used, merely by way of example, for producing a reaction liquid for multiplexed detection in the chip with the evaluation cavities 345.

[0057] In other words, this embodiment example has additional microfluidic elements, which can in particular be used for further sample analysis of the sample material purified by the treatment apparatus 100. In addition to the integration of further chambers for an upstream arrangement of further dry reagents, for example constituents for carrying out further detection and/or amplification reactions, the treatment apparatus 100 in this embodiment example has a unit for aliquoting or partitioning the processed sample liquid. In a particularly advantageous manner, by an upstream arrangement of further dry reagents in the evaluation cavities 345 for aliquoting in the individual aliquots, different detection reactions for addressing different targets in the sample liquid can be carried out independently of one another. In this manner, which can also be referred to as geometric multiplexing, a sample liquid can be examined for the presence of a variety of different features. In a further embodiment example, the chip having the evaluation cavities 345 permits microfluidic generation of a particularly high number of aliquots of the processed sample liquid, in particular more than 1000 partitions. In this manner, digital sample analysis is enabled. In doing so, approximately a copy number of targets initially present in a sample liquid can be quantified with absolute accuracy.

[0058] FIG. 4 illustrates a schematic plan view of an embodiment example of a treatment apparatus 100 having a channel system expansion module 300. This can be the treatment apparatus described in the previous figures and the channel system expansion module described in FIG. 3.

[0059] In this embodiment example, the treatment apparatus 100 comprises an upstream arrangement chamber 310, a further upstream arrangement chamber 350, and an evaluation chamber 330, which is provided for accommodating and microfluidically processing a chip having evaluation cavities 345.

[0060] In this embodiment example, the microfluidic treatment apparatus 100 is inclined against the direction of action of a gravitational field at an angle of about 30°. In a further embodiment example, the treatment apparatus 100 is oriented at a predetermined angular range of between 0° and 45° to the field lines of the earth gravitational field with a gravity acceleration of approximately 9.81 m/s.sup.2. With a suitable orientation of the upstream arrangement chamber 310 and the adjacent microfluidic channels in the treatment apparatus 100, it is achieved that gas bubbles which form upon dissolution of the reagent are discharged due to the buoyancy acting on the gas bubbles due to the density difference compared to the surrounding liquid, driven by gravity, whereas the reaction liquid is free of gas bubbles and further usable. The reaction liquid can then be used, for example, to carry out a polymerase chain reaction in the treatment apparatus 100 so as to amplify constituents of the eluate, which are, merely by way of example, predetermined nucleic acid sequences, and to thus make them accessible for a subsequent detection reaction. The subsequent detection reaction in this embodiment example is an amplification reaction, which is carried out in an array format in order to detect different targets based on a fluorescence signal. In a further embodiment example, the subsequent detection reaction is a hybridization reaction, which is carried out in an array format in order to detect different targets based on a bioluminescence signal.

[0061] FIG. 5A is a flow chart of an embodiment example of a method 500 for operating a microfluidic treatment apparatus. This can be the treatment apparatus described in the previous figures.

[0062] The method 500 has a step 505 of introducing a sample liquid into the microfluidic treatment apparatus. In addition, the method 500 has a step of extraction 510 sample constituents present in the sample liquid through a filter element, wherein a connection of constituents present in the sample liquid, which in this embodiment example are nucleic acids, is made to the filter element located in the filter chamber. In order to improve or allow a binding of the constituents to the filter, this step is carried out, merely by way of example, by pumping a binding buffer. As described above, the extraction and an optional subsequent step of washing the filter element via channel inlet 110, filtering branch 125, and channel outlet 150 can occur, wherein no liquid or as little liquid as possible is directed into the pumping branch 155, in particular by closing the pumping valves 165a, 165b, and preferably also by closing the further pumping valves 175a, 175b. In addition, the method 500 has a step of elution 515 sample constituents from the filter element. In doing so, sample components bound to the filter are dissolved. The elution can be carried out via a flushing through the pumping branch 155 and the filtering branch 125, in particular via a repeated, circular flushing, in particular when the inlet valve 115 and the outlet valve 152 are closed and when the pumping valves 165a, 165b and, if present, preferably the further pumping valves 175a, 175b are opened. This is merely by way of example, using an elution buffer in which the constituents are present after dissolving. In a further embodiment example, a flushing of the microfluidic channel with an elution buffer occurs prior to the actual elution, separating the filter chamber by means of the microfluidic filter valves in order to remove residues of the binding buffer and the wash buffer.

[0063] FIG. 5B shows a block diagram of an embodiment example of a control unit 550 for operating a microfluidic treatment apparatus according to a variant presented herein. The control unit comprises a unit 555 for controlling an introduction of a sample liquid into the microfluidic treatment apparatus. Further, the control unit 550 comprises a unit 560 for controlling an extraction of sample constituents present in the sample liquid through a filter element and a unit 565 for controlling an elution of sample constituents from the filter element.

[0064] FIG. 6 shows a flow chart of an embodiment example of a method 500 for operating a microfluidic treatment apparatus with an additional step of lysing 600 and an additional step of washing 605. This can be the method described in FIG. 5.

[0065] In this embodiment example, following step of insertion 505 and prior to step of extraction 510, there is a step of lysing 600 the sample liquid, in which a lysis of constituents present in the sample liquid, such as bacteria or cells, is carried out. The lysis is done, merely by way of example, by adding a lysis buffer to the sample liquid, wherein the lysis buffer mixed with the sample liquid is subsequently, in a step of extraction 510, conducted via the channel inlet 110, the filtering branch 125, and the channel outlet 150, in particular with the first pumping valve 165a closed and the further first pumping valve 175a closed, and an enrichment of sample constituents released during lysis, for example nucleic acids, can occur on the filter element. In a further embodiment example, the lysis is carried out by an ultrasonic effect. In addition, in this embodiment example, the method 500 has a step of washing 605 the filter element and the filter chamber following the step of extraction 510 and prior to the step of elution 515, wherein the step of washing 605 can occur as described above in FIG. 5 via the following short path: channel inlet 110 — filtering branch 125 — channel outlet 150. In the step of washing 605, in particular, residues of the binding buffer located in the vicinity of the filter chamber are removed and replaced by the washing buffer.

[0066] FIG. 7 illustrates a flow chart of an embodiment example of a method 500 for operating a microfluidic treatment apparatus having a channel system expansion module 300. This can be the method described in FIG. 5 and in FIG. 6.

[0067] In this embodiment example, the method 500 following the step of elution 515 has an additional step of providing 700 a reaction liquid by dissolving a reagent using the sample ingredients. The step of providing 700 a reaction liquid can also be referred to as a bead-dissolving step. At least a part of the previously obtained eluate is transferred to an upstream arrangement chamber described in FIG. 3 in order to dissolve a reagent upstream therein and to produce a reaction liquid for a first amplification reaction.

[0068] Additionally, in this embodiment example, the method 500 has a step of carrying out 705 an amplification reaction. The reaction liquid generated is, merely by way of example, heated cyclically in the treatment apparatus to two different temperature levels in two pumping chambers arranged in series and detachable by pumping valves, in particular in one or more of the pumping chambers 160a, 160b, 160c in the pumping branch 155. In this embodiment example, the temperature-control is used in order to carry out a multiplexed polymerase chain reaction.

[0069] In a further embodiment example, the step of carrying out 705 an amplification reaction is followed by a step of diluting the reaction liquid containing the reaction products from the first amplification reaction.

[0070] Further optionally, in a further embodiment example, after the step of carrying out 705 an amplification reaction, a step of temperature-control is carried out in order to cause a denaturation of constituents of the reaction liquid. Further optionally, in a further embodiment example, after the step of carrying out 705 an amplification reaction, a step of adding further reagents is carried out, for example in liquid or in solid form, for example freeze-dried or lyophilized.

[0071] In this embodiment example, after the step of carrying out 705 an amplification reaction, the step of providing 700 a reaction liquid is repeated. A portion of the diluted reaction liquid containing a portion of the reaction products from the first amplification reaction is used in order to thereby dissolve a further bead in the further upstream arrangement chamber and to produce a reaction liquid for carrying out a detection reaction.

[0072] In addition, in this embodiment example, the method 500 has an additional step of aliquoting 710 the reaction liquid. In doing so, a portion of the reaction liquid is distributed from the step of providing 700 a reaction liquid to at least two reaction compartments. For the generation of the reaction compartments, only a part of the liquid via the evaluation chamber described in FIG. 3 is transferred to the microcavities, and subsequently the microcavities are sealed by the introduction of a further liquid, which is not mixable with the reaction liquid, into the evaluation chamber, so that microfluidic reaction compartments, which are subsequently separated from one another and consist of parts, or aliquots, of the reaction liquid, are present in the microcavities. In the individual microcavities, in this embodiment example, target-specific reagents are arranged upstream so as to examine the present aliquoted liquid for the presence of different targets.

[0073] In this embodiment example, the method 500 additionally has a step of carrying out 715 a detection reaction, in particular in the evaluation chamber 330. The detection reaction is, merely by way of example, a second amplification reaction, specifically a polymerase chain reaction, wherein the microcavities and the microfluidic reaction compartments located therein are temperature-controlled so as to allow further amplification reactions to be carried out therein. In a further embodiment example, the detection reaction is an isothermal amplification variant.

[0074] In addition, in this embodiment example, the method 500 has an additional step of evaluating 720 a reaction result, in particular in the evaluation chamber 330. The evaluation is carried out, merely by way of example, using visual analysis of a fluorescence signal caused by probe molecules present in the individual reaction compartments. Based on the signal, the sample liquid can thus be tested for the presence of different target substances. In a further embodiment example, the step of evaluation 720 occurs in parallel to the carrying out 715 of a detection reaction.

[0075] In other embodiments of the method 500, individual steps can be carried out repeatedly, their order can be swapped, or they can be omitted entirely.

[0076] In other words, the treatment apparatus presented herein can be described as follows:

[0077] The treatment setup described in the preceding figures is characterized by a particularly high variability of the adjustable flow rates and pumping characteristics for the processing of the filter element, in particular by the use of at least two different types of active microfluidic elements for the generation of a flow. That is to say, in particular, by membrane-based elements having at least two different liquid displacement volumes, in particular suitably sized pumping chambers and pumping valves as described in the previous figures. In addition, the treatment setup has a suitable arrangement and number of microfluidic elements, in order to, for example, enable a peristaltic pumping with at least three elements, wherein the volume of liquid transported in a step corresponds to the displacement volume of an element, or in order to achieve, for example, a unidirectional or bi-directional pumping using four same elements, wherein the transportable volume of liquid corresponds to the displacement volume of two elements. In addition, in the treatment setup described in the preceding figures, a use of different actuation sequences of the microfluidic elements is possible, with an adjustable actuation frequency and sequence of actuation of the microfluidic elements, in order to enable a peristaltic pumping or shuttle pumps, in particular bidirectionally in the microfluidic channel and in particular through the filter chamber with the filter element. In addition, the treatment setup described in the preceding figures allows for a particularly advantageous connection of the treatment apparatus, which can also be referred to as the purification unit, to a microfluidic network as well as a particularly space-saving arrangement and efficient and repeated use of the microfluidic elements forming the purification unit. In particular, this can be realized by an implementation of three pumping chambers arranged in series in the microfluidic channel system, which can be separated from the microfluidic channel system and the microfluidic network surrounding the treatment apparatus by two valves adjacent to the two outer of the three pumping chambers, and which can in particular be temperature-controlled individually, that is to say substantially independently, of one another. In this manner, with a suitable temperature-control, the three isolated pumping chambers can be used in order to periodically bring a liquid plug therein to different temperatures, for example to carry out a polymerase chain reaction in the liquid plug.

[0078] In addition, the treatment setup described in the previous figures has a low dead volume, in particular of a wash buffer which undesirably reaches an elution buffer, in particular by an arrangement of the two filter valves surrounding the filter chamber with the filter element so as to be as spatially close as possible and the adjacent T-shaped channel-crossover elements and/or a minimization of the channel volume present therein.

[0079] In addition, the treatment setup described in the preceding figures is characterized by the possibility of processing variable liquid volumes, in particular by an implementation of a total of four pumping chambers in the purification unit, in order to process a liquid plug which has substantially the displacement volume of one or two of the pumping chambers in the purification unit. Also, the possibility of embedding the volume of sample liquid to be processed into a second non-mixable liquid phase can favor the treatment process.