GB2538357A

GB2538357A - Purification unit for increasing the purity of at least one substance taken from a sample liquid, purification apparatus, method for operating a purification

Info

Publication number: GB2538357A
Application number: GB1604395.2A
Authority: GB
Inventors: Hoehl Melanie; Mueller Matthias
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2015-03-18
Filing date: 2016-03-15
Publication date: 2016-11-16
Anticipated expiration: 2036-03-15
Also published as: GB201604395D0; GB2538357B; GB2538357A8; DE102015204882A1

Abstract

A purification unit 100 for increasing the purity of at least one substance 124 taken from a sample liquid 122, the unit comprising a sample chamber 104 for receiving the sample liquid 122, a reagent chamber 104 for receiving a reagent 122, a filter device 106 connected or connectable to the reagent chamber 102 via a reagent channel 108 and to the sample chamber 104) via a sample channel 110 for filtering the substance 124 out of the sample liquid 122 using the reagent 120, a holding device 116 for holding an interchangeable collecting vessel 114 beneath an outflow 112 of the filter device 106 to collect the substance 124, and an interface 118 to a pressure controller (302; fig 3) for controlling a transport of liquid within the unit by subjecting the interface 118 to a pneumatic pressure. Ideally, the filter device comprises a mixing chamber for mixing the sample and reagent, and a filter. The unit ideally has a laminate structure with the pneumatic pressure created by depressing a layer. The unit (fig 2) may comprise multiple reagent chambers, sample chambers, filtering devices and waste outlets.

Description

Description Title

Purification unit for increasing the purity of at least one 5 substance taken from a sample liquid, purification apparatus, method for operating a purification unit, and method for producing a purification unit State of the Art The present invention relates to a purification unit for increasing the purity of at least one substance taken from a sample liquid, to a purification apparatus, to a method for operating a purification unit, to a method for producing a purification unit, to a corresponding apparatus and also to a corresponding computer program.

For the implementation of biochemical processes, so-called lab-on-a-chip systems -also called pocket-sized laboratories or chip laboratories -are increasingly coming into operation. Here it is a question of, for example, microfluidic systems in which an entire functionality of a macroscopic laboratory can be accommodated on a synthetic substrate roughly the size of a plastic card. In addition, purification is presently feasible only manually via columns, precipitating out, or by means of automated pipetting systems, which is very expensive, particularly on a laboratory scale.

Disclosure of the Invention

Against this background, with the approach presented herein a purification unit for increasing the purity of at least 5 one substance taken from a sample liquid, a purification apparatus, a method for operating a purification unit, a method for producing a purification unit, furthermore an apparatus that uses these methods, as well as, finally, a corresponding computer program will be presented, according 10 to the main claims. Advantageous configurations result from the respective dependent claims and the following description.

The approach presented herein creates a purification unit 15 for increasing the purity of at least one substance taken from a sample liquid, said purification unit exhibiting the following features: a sample chamber for receiving the sample liquid; a reagent chamber for receiving a reagent; a filter device, connected or connectable to the reagent chamber via a reagent channel and to the sample chamber via 25 a sample channel, for filtering the substance out of the sample liquid, using the reagent; a holding device for arranging and/or holding an interchangeable collecting vessel at an outflow of the 30 filter device, in order to collect the substance; and an interface to a pressure controller for controlling a transport of liquid within the purification unit by subjecting the interface to a pneumatic pressure.

The purification unit may, for example, have been realised as a laminated composite consisting of several layers of synthetic material, in particular consisting of polymer substrates and flexible polymer membranes. A substance to be purified may be a biochemical substance such as nucleic acids for instance, in particular DNA, RNA or proteins. These can be lysed and/or extracted from a matrix either on the chip or outside the apparatus that is being presented in this patent, for example cell material (blood, cell culture, foodstuffs, tissue, saliva, body fluids, plants etc.). Lysis may take place either with reagents by virtue of a chemical reaction, and/or thermally and/or electrically and/or by means of ultrasound. By a reagent', a substance may be understood that in conjunction with the sample liquid brings about a chemical reaction. For example, the reagent may be an elution buffer, wash buffer, binding buffer or/and lysis buffer. By a 'filter device', a device for generating a mixture consisting of the sample liquid and the reagent and also for extracting the substance from the mixture may be understood, for instance. By a 'collecting vessel', a microreaction vessel may be understood, in particular a sample-collecting vessel (e.g. PCR tube or Eppendorf tube -'Eppi'). The collecting vessel may, for example, be capable of being inserted manually into the holding device, in particular capable of clicking into place. By an interface', a pressure port for connecting the pressure controller to the purification unit may be understood. For example, the interface may have been formed in order to be pneumatically coupled with a pressure port of the pressure controller already when the purification unit is being inserted into the pressure controller. By a 'pneumatic pressure', an overpressure or underpressure, i.e. a positive or negative relative pressure with respect to an atmospheric pressure, or the atmospheric pressure may be understood. The pressure controller may have been designed to generate the pneumatic pressure and to pass this pressure on to the purification unit via the interface. In this regard, a variety of valves as well as pumping chambers can be driven pneumatically via a separate pneumatic layer and a flexible membrane. This is then effected, for example, in such a form that by virtue of a pressurising of this pneumatic layer of the laminated composite a depressing of this layer into the region of the corresponding chamber (for example, reagent chamber or sample chamber) or the valve (for example, reagent valve or sample valve) occurs, so that the volume in the chamber is diminished (and by this means the fluid located in the chamber is conveyed out), or that the cross section of passage in a channel beneath the pneumatic layer in the region of the valve in question is diminished after the subjecting of the pneumatic layer to the compressed air, and by this means this channel as a valve is blocked.

The approach proposed herein is based on the perception that a pressure-controlled lab-on-a-chip cartridge for increasing the purity of biochemical substances may exhibit a holder for an interchangeable microreaction vessel. Advantageously, the microreaction vessel held in the cartridge can be filled with the purified substances already during a purification process. Accordingly, the substances can be subjected to further processing directly by simple withdrawal of the microreaction vessel after completion of the purification process. Manual decanting can consequently be dispensed with. As a result, contaminations of the purified substances can be avoided. The user is also protected from hazardous substances by the completely closed and automated system.

A lab-on-a-chip system typically consists of two main components: on the one hand, a test carrier or a single-use cartridge with structures and mechanisms for realizing fluidic basic operations, such as, for instance, mixers which may consist of passive components such as channels, reaction chambers, prestored reagents or even of active components such as valves or pumps; on the other hand, actuating units, detecting units and control units. Such a system makes it possible, for example, to carry out biochemical processes completely automatically.

Pressure-controlled systems are also known that exhibit a channel structure with valves and pumps for transporting liquid. Such functional elements may have been realised, for example, with the aid of two polymer substrates which have been separated by a flexible polymer membrane. For example, the polymer membrane may be deflected by pneumatic pressures, in order to displace liquids within the system or to seal a channel. For this purpose, both positive and negative relative pressures can be generated in an external drive unit and can be passed on to the system. An associated drive appliance can, for example, make underpressure, overpressure and atmosphere available to a pneumatic interface. Such a drive appliance offers the advantage of a small space requirement.

Furthermore, in a pressure-controlled cartridge additional functions -for instance, a heated purification filter or various chambers -can be realised with relatively little manufacturing effort. For example, requisite volumes in the interior of the cartridge can be varied via a thickness of the cartridge without serious design alterations.

Complex biochemical functions such as polymerase chain reactions (PCR) and detection methods, for example an optical readout after a hybridization reaction, after a polymerase chain reaction or after enzyme assays or immune assays, can be integrated into the cartridge relatively easily and inexpensively.

A purification unit according to the features of the approach described herein accordingly has the advantage that the purification can be carried out in fully automated manner, by virtue of which the treatment-time in the course of purification can be distinctly reduced in comparison with manual process sequences. In addition, through the use of interchangeable collecting vessels -in particular, Eppis -handling errors can be avoided. A further advantage results from the fact that the purification unit can be operated with the aid of a simple and inexpensive drive appliance. Depending on the form of implementation, the drive appliance can be used not only for the purification of DNA but also, for example, for the implementation of a full diagnostic process chain with amplification etc. According to a form of implementation described further below, the purification unit can also be employed, for example, for parallel purification of nucleic acids, in particular DNA.

The purification unit may have been provided with at least one sample pumping chamber which may be connected or connectable to the sample channel and which may be capable of being subjected to a pneumatic pressure via the interface, in order to pump the sample liquid through the sample channel. Additionally or alternatively, the sample channel may exhibit at least one sealing unit for sealing the sample channel, for instance a siphon structure or a normally-closed valve. Such a sample pumping chamber can be realised easily and enables a precise metering of the sample liquid.

It is advantageous, furthermore, if the filter device exhibits at least one mixing chamber, for mixing the sample liquid and the reagent, and a filter for filtering out the substance. The mixing chamber may be connected or connectable to the reagent chamber via the reagent channel and to the sample chamber via the sample channel. The filter may be connected or connectable to the mixing chamber and to the outflow via an outflow channel. In particular, the outflow channel may exhibit at least one outflow valve arranged between the filter and the outflow. Such a filter device offers the advantage of a simple and inexpensive structure and a reliable mode of operation.

It is particularly favourable if the sample pumping chamber is connected or connectable, via a control channel, to a section of the outflow channel located between the mixing chamber and the filter. In particular, the control channel may exhibit at least one first control valve. Additionally or alternatively, the sample channel may exhibit at least one second control valve, arranged between the mixing chamber and the sample pumping chamber, for controlling a mixing circuit. By a 'mixing circuit', a pumping-round of the sample liquid and of the reagent though the mixing chamber, through the control channel and through the sample channel may be understood, for example. By this means, the sample liquid and the reagent can be thoroughly mixed with one another.

Moreover, the purification unit may exhibit at least one waste container which may be connected or connectable, via a waste channel, to a section of the outflow channel located between the filter and the outflow. In particular, the waste channel may exhibit at least one waste valve and, additionally or alternatively, may lead into the outflow channel between the filter and the outflow valve. By virtue of a waste container coupled with the filter device in such a manner, the collecting vessel placed beneath the outflow can be prevented from being contaminated with waste products.

According to a further form of implementation, the purification unit exhibits at least one reagent pumping chamber which is connected or connectable to the reagent channel and may be capable of being subjected to a pneumatic pressure via the interface, in order to pump the reagent through the reagent channel. In particular, the reagent channel may exhibit at least one reagent-chamber valve, arranged between the reagent chamber and the reagent pumping chamber, and, additionally or alternatively, a mixing-chamber valve arranged between the mixing chamber and the reagent pumping chamber. This form of implementation enables a precise metering of the reagent in the course of transport into the filter device.

The purification unit may exhibit at least one further reagent chamber for receiving a further reagent. The 10 filter device may be connected or connectable to the further reagent chamber via the reagent channel, in order to filter the substance out of the sample liquid, using the further reagent. This form of implementation has the advantage that, depending on the type of the substance to be extracted from the sample liquid, differing reagents can be introduced in succession into the filter device, in order to carry out the purification.

Particularly advantageous is a form of implementation in which the purification unit exhibits at least one further sample chamber for receiving a further sample liquid, a further filter device, connected or connectable to the reagent chamber via the reagent channel and to the further sample chamber via the further sample channel, for filtering at least one substance out of the further sample liquid, using the reagent, and a further holding device for arranging and/or holding an interchangeable further collecting vessel beneath an outflow of the further filter device. This form of implementation enables a parallelised purification of substances taken from differing sample liquids.

In this regard, the further filter device may be connected or connectable to the further reagent chamber via the reagent channel, in order to filter the substance out of the further sample liquid, using the further reagent. As a result, parallel purifications with several partial reactions can be carried out without manual intermediate steps.

The approach presented herein creates, in addition, a 10 purification apparatus having the following features: at least one purification unit according to one of the forms of implementation described herein; and a pressure controller which has been connected to the interface of the purification unit, in order to control a transport of liquid within the purification unit by subjecting the interface to a pneumatic pressure.

Furthermore, the approach described herein creates a method for operating a purification unit according to one of the forms of implementation described herein, said method including the following step: subjecting the interface to a pneumatic pressure by means of the pressure controller, in order to filter the substance out of the sample liquid, using the reagent, whereby the substance is collected by the collecting vessel.

For example, in the pressurising step the interface may be subjected in succession to differing pressures, in order to bring about a transport of liquid in different directions of flow within the purification apparatus.

Before the substance is conducted out of the filter device, 5 the collecting vessel can be placed and fastened in the holding device manually. Alternatively, the purification unit may have been preassembled with the collecting vessel. After the filling of the collecting vessel, the collecting vessel can be withdrawn. The substance located therein can 10 be examined further, for example in a following analytical method which can be carried out in a manner locally separated from a purification method carried out by means of the purification unit.

Finally, the approach proposed herein creates a method for producing a purification unit for increasing the purity of at least one substance taken from a sample liquid, said method including the following step: forming a laminated composite, in particular a polymeric laminated composite, with a sample chamber for receiving the sample liquid, with a reagent chamber for receiving a reagent, with a filter device, connected or connectable to the reagent chamber via a reagent channel and to the sample chamber via a sample channel, for filtering the substance out of the sample liquid, using the reagent, with a holding device for arranging and/or holding an interchangeable collecting vessel beneath an outflow of the filter device, in order to collect the substance, and with an interface to a pressure controller for controlling a transport of liquid within the purification unit by subjecting the interface to a pneumatic pressure.

By virtue of such a method, the purification unit can be produced particularly inexpensively.

The approach presented herein furthermore creates an apparatus that is designed to carry out, to drive or to realise the steps of a variant of a method presented herein in appropriate devices. Also by virtue of this practical variant of the invention in the form of an apparatus, the object underlying the invention can be achieved quickly and efficiently.

By an 'apparatus', in the present case an electrical appliance may be understood that processes sensor signals and outputs, in a manner depending thereon, control signals and/or data signals. The apparatus may exhibit an interface which may take the form of hardware and/or software. In the case of a hardware design, the interfaces may be, for example, part of a so-called system ASIC which comprises highly diverse functions of the apparatus. However, it is also possible that the interfaces are individual integrated circuits or consist at least partly of discrete structural elements. In the case of a software design, the interfaces may be software modules which, for example, are present on a microcontroller alongside other software modules.

Also an advantage is a computer-program product or computer program with program code which may have been stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard-disc memory or an optical memory and which is used for implementing, realising and/or driving the steps of the method according to one of the forms of implementation described above, in particular when the program product or program is executed on a computer or on an apparatus.

The approach presented herein will be elucidated in more detail below in exemplary manner with reference to the appended drawings. Shown are: Fig. 1 a schematic representation of a purification unit according to an embodiment of the present invention; Fig. 2 a schematic representation of a purification unit with several sample chambers and reagent chambers according 15 to an embodiment of the present invention; Fig. 3 a schematic representation of a purification apparatus according to an embodiment of the present invention; Fig. 4 a flow chart of a method for operating a purification unit according to an embodiment of the present invention; Fig. 5 a flow chart of a method for producing a purification unit according to an embodiment of the present invention; Fig. 6 a schematic representation of an apparatus for operating a purification unit according to an embodiment of the present invention; and Fig. 7 a schematic representation of an apparatus for producing a purification unit according to an embodiment of the present invention.

In the following description of favourable embodiments of the present invention, identical or similar reference symbols will be used for the similarly acting elements represented in the various Figures, in which connection a repeated description of these elements will be dispensed with.

Fig. 1 shows a schematic representation of a purification unit 100 according to an embodiment of the present invention. The purification unit 100 exhibits a reagent chamber 102, a sample chamber 104 and also a filter device 106. The filter device 106 has been fluidically coupled with the reagent chamber 102 via a reagent channel 108 and with the sample chamber 104 via a sample channel 110. Located below an outflow 112 of the filter device 106 is a collecting vessel 114 which is held by a holding device 116 in such a manner that an opening of the collecting vessel 114 is situated opposite the outflow 112. Depending on the form of implementation, the collecting vessel 114 may have been inserted into the holding device 116, suspended therein or clicked into place therein.

The purification unit 100 has furthermore been designed with an interface 118 which can be pneumatically coupled with a pressure controller for generating a pneumatic pressure. Via the interface 118, the pneumatic pressure can be conducted through the purification unit 100, in order to transport liquids within the purification unit 100. This transporting of the liquid may be effected, for example, by a pneumatic layer of the laminated composite of the purification unit 100 being subjected to a pneumatic pressure and being depressed by this means. This depressing causes the volume in the chamber located beneath the depressed region of the pneumatic layer to be diminished, so that the liquid in this chamber is then conveyed out. If a channel has been arranged beneath the depressed region of the pneumatic layer, this region can be used as a valve, since by virtue of the depressed part of the pneumatic layer the channel has then been sealed or the passageway has been considerably impaired.

The interface 118 can be subjected to the pneumatic pressure in such a manner that a reagent 120 located in the reagent chamber 102 is pumped through the reagent channel 108 into the filter device 106 and a sample liquid 122 located in the sample chamber 104 is pumped through the sample channel 110 into the filter device 106. The filter device 106 serves, for example, to form a mixture consisting of the two liquids 120, 122 and to extract from this mixture a substance 124 which via the outflow 112 is conducted into the collecting vessel 114 and collected therein. The purification process carried out for the purpose of increasing the purity of the substance 124 in the filter device 106 can be controlled pneumatically via the interface 118.

Fig. 2 shows a schematic representation of a purification 30 unit 100 with several sample chambers and reagent chambers according to an embodiment of the present invention. The purification unit 100 is, for example, a purification unit described with reference to Fig. 1. According to the embodiment shown in Fig. 2, the filter device 106 exhibits a mixing chamber 200 and a filter 202 which has been fluidically connected to the mixing chamber 200 and to the outflow 112 via an outflow channel 204. The outflow channel 204 may have been formed at least partly in a second plane of the purification unit 100. A reagent pumping chamber 206 which is capable of being subjected to a pneumatic pressure via the interface 118 has been fluidically connected both to the reagent chamber 102 and to the mixing chamber 200 via the reagent channel 108. By means of the reagent pumping chamber 206, the reagent can be pumped through the reagent channel 108 into the mixing chamber 200. For the purpose of controlling a stream of liquid between the reagent chamber 102 and the reagent pumping chamber 206, a subsection of the reagent channel 108 extending between the reagent chamber 102 and the reagent pumping chamber 206 exhibits a reagent-chamber valve 208. In addition, in a subsection of the reagent channel 108 connecting the reagent pumping chamber 206 to the mixing chamber 200 a mixing-chamber valve 210 has been arranged which serves for controlling a stream of liquid between the reagent pumping chamber 206 and the mixing chamber 200.

The sample channel 110 has been fluidically connected to a sample pumping chamber 212 which is capable of being subjected to a pneumatic pressure via the interface 118. The sample pumping chamber 212 has furthermore been fluidically connected, via a control channel 216, to a subsection of the outflow channel 204 connecting the mixing chamber 200 to the filter 202. In the control channel 216 a first control valve 218 for controlling a stream of liquid has been arranged between the outflow channel 204 and the sample pumping chamber 212. Similarly, a subsection of the sample channel 110 located between the sample pumping chamber 212 and the sample chamber 104 has been connected to the mixing chamber 200 via a second control valve 220. The second control valve 220 serves for controlling a stream of liquid between the mixing chamber 200 and the sample pumping chamber 212 or the sample chamber 104. The sample pumping chamber 212 serves, on the one hand, for pumping the sample liquid into the mixing chamber 200. On the other hand, the sample pumping chamber 212 may be utilised in order to pump liquids located in the mixing chamber 200 -for instance, the reagent and the sample liquid -in a circuit via the sample channel 110 and the control channel 216, in order to mix the liquids with one another. Subsequently the mixture can be conducted across the filter 202, in order to filter the substance out of the mixture.

According to the embodiment shown in Fig. 2, the sample channel 110 additionally exhibits between the second control valve 220 and the sample chamber 104 a sealing unit 222, for example a normally-closed valve or a siphon structure.

Located below the collecting vessel 114 -here, an Eppi clicked into the holding device 116 -is a waste container 224 which, via a waste channel 226, leads into a subsection of the outflow channel 204 connecting the filter 202 to the outflow 112. A stream of liquid through the waste channel 226 can be controlled by means of a waste valve 228.

Between the outflow 112 and a connecting point between the waste channel 226 and the outflow channel 204 the outflow channel 204 exhibits an outflow valve 230 which is designed to control a stream of liquid between the filter 202 and the outflow 112.

In addition to the reagent chamber 102, the purification unit has been constructed in exemplary manner with four further reagent chambers 232, 234, 236, 238 for prestoring further reagents. Depending on the form of implementation, in reagent chamber 102 an elution buffer, in further reagent chamber 232 a wash buffer 2, in further reagent chamber 234 a wash buffer 1, in further reagent chamber 236 a binding buffer, and in further reagent chamber 238 a lysis buffer with enzymes may have been prestored.

The further reagent chambers have been fluidically connected to the reagent pumping chamber 206 via the reagent channel 108. More precisely, the further reagent chambers have been connected to a main branch of the reagent channel 108 via a respective sub-branch. In the sub-branches further reagent-chamber valves 240, 242, 244, 246 for controlling a stream of liquid have been arranged between the further reagent chambers and the main branch of the reagent channel 108.

According to Fig. 2, the purification unit 100 exhibits a further sample chamber 248 for receiving a further sample liquid. The further sample chamber 248 has been fluidically connected to a further filter device 252 via a further sample channel 250. The further filter device 252 corresponds, for example, to filter device 106 described further above with reference to Fig. 2. A mixing chamber of the further filter device 252 has been fluidically connected to the reagent pumping chamber 206 via the reagent channel 108, so that the reagents located in reagent chambers 102 to 238 can be pumped on demand by means of the reagent pumping chamber 206 also into the mixing chamber of the further filter device 252.

Located below an outflow 254 of the further filter device 252 is a further collecting vessel 256, here likewise an Eppi, which is held by a further holding device 258 in such a manner that an opening of the further collecting vessel 256 is situated opposite the outflow 254, so that a substance purified by extraction from the further sample liquid by means of the further filter device 252, using one or more reagents, is collected by the further collecting vessel 256 upon being conducted out of the filter device 252.

As can be discerned in Fig. 2, a first purification train 260, formed by the sample chamber 104, the filter device 106 and the holding device 116, and a second purification train 262, formed by the further sample chamber 248, the further filter device 252 and the further holding device 258, may be of substantially identical construction.

In Fig. 2, in addition to the two purification trains 260, 262, in exemplary manner a third purification train 264 with a further sample chamber 266, with a further filter device 268, with a further holding device 270 and with a further collecting vessel 272, and also a fourth purification train 274 with a further sample chamber 276, with a further filter device 278, with a further holding device 280 and with a further collecting vessel 282, have been represented. Purification trains 264, 274 may have been constructed to be identical to the second purification train 262, in which case the respective mixing chambers of the further filter devices 252, 268, 278 have been fluidically coupled with the reagent pumping chamber 206 via the reagent channel 108.

According to an embodiment, the schematic top view of an exemplary lab-on-a-chip design shown in Fig. 2 serves for parallel purification of several different samples -here, in exemplary manner, four samples. For this purpose, the purification unit 100 -for example, a cartridge -contains five common reagent-prestorage chambers 102, 232, 234, 236, 238 with the reagent pumping chamber 206, a waste reservoir 224 and four sample input chambers 104, 248, 266, 276 with the associated sample pumping chambers 212, mixing chambers 200, filters 202 -for instance, silica filters -and click-in Eppis as collecting vessels 114, 256, 272, 282.

Depending on the form of implementation, the purification unit 100 may exhibit more or fewer than five reservoirs for prestoring reagents in liquid form. The reagents may have 25 been packed in stick packs or blisters.

The four different samples can be input in liquid form into the four sample chambers 104 to 276. The size of the chambers may vary, depending on the quantity of liquid employed. For example, the size may be between 100 pl and 5 ml, in particular about 500 pl. The volume can be adapted by varying the thickness of the cartridge.

Moreover, the purification unit 100 includes a fluidic network of channels, valves and active pumping chambers, in order to transport the reagents into the mixing chambers 200 and to mix them, to conduct them across the filters 202, and finally to collect them in the click-in microreaction vessels 114. For the purpose of binding DNA, use may be made of silica filters, for example, as filters 202.

Fig. 3 shows a schematic representation of a purification apparatus 300 according to an embodiment of the present invention. The purification apparatus 300 includes a pressure controller 302 and a purification unit 100, for example a purification unit such as has been described in the foregoing with reference to Figures 1 and 2. According to this embodiment, the purification unit 100 has been inserted into the pressure controller 302 in such a manner that the interface 118 has been pneumatically coupled with a pressure port 304 of the pressure controller 302. The pressure controller 302 is designed to subject the interface 118 to the pneumatic pressures required for transporting liquids in the purification unit 100.

According to an embodiment, the pressure controller 302 is designed to set three different pressure levels which, for example, may serve for driving a purification of DNA that is capable of being carried out by means of the purification unit 100. This has the advantage that the pressure controller 302 can be constructed particularly inexpensively, since additional functions -such as, for instance, a temperature regulation or an optical evaluating unit -may be dispensed with.

Fig. 4 shows a flow chart of a method 400 for operating a purification unit according to an embodiment of the present invention. The method 400 can, for example, be carried out in connection with a purification unit described in the foregoing with reference to Figures 1 to 3. The method 400 includes a step 401 in which the interface of the purification unit is subjected to a pneumatic pressure by means of the pressure controller, in order to filter the substance out of the sample liquid, using the reagent. In this process, the substance is collected by the collecting vessel held by the holding device.

According to an embodiment, the method 400 can be used for carrying out a DNA purification process in the purification unit. Such a DNA purification process may consist of the following steps.

In a first step, a liquid sample is input into the sample chamber, in which connection the reagents required for purification may have been prestored in the corresponding reagent chambers of the purification unit. After this, the purification unit is sealed and inserted into an appropriate drive appliance, for instance a pressure controller described further above.

In a second step, the reagent containers, also called 30 reagent chambers, are opened.

In a third step, a binding buffer is transported to the mixing chamber. A quantity of the binding buffer may be set in such a way that suitable binding conditions prevail for binding DNA on the silica filter.

In a fourth step, the sample is transported out of the sample chamber into the mixing chamber.

In a fifth step, the total quantity consisting of sample 10 and binding buffer is mixed by being pumped round in a mixing loop.

In a sixth step, the contents of the mixing chamber are transported across the silica filter. A dwell-time may be inserted between individual pumping strokes. The dwell-time may correspond to a binding-time required for binding the DNA to the silica filter. In this case the DNA is bound on the integrated filter.

In a seventh step, a first wash buffer is transported across the silica filter. As a result, the DNA is freed of contaminants such as proteins, for example. Meanwhile, the DNA remains bound on the integrated filter. A liquid conducted through the filter is collected in a waste chamber, also called a waste container further above.

In an eighth step, a second wash buffer is transported across the silica filter. A further cleaning step takes place, in which the DNA is again freed of contaminants while it remains on the filter. Once again, in this process a liquid conducted through the filter is collected in the waste chamber.

In a ninth step, an elution buffer is transported across the silica filter. By virtue of the elution buffer, the DNA is detached from the silica filter and collected in Eppis which have been clicked into the purification unit.

In a tenth step, the Eppis with the purified sample are withdrawn.

Steps three to nine may be substeps of step 401 and may be carried out by subjecting the interface of the purification unit to appropriate pneumatic pressures.

Optionally, a further pumping chamber may be inserted into 15 each purification train, in order to enable a multiple elution across the filters by pumping back and forth.

According to a further embodiment, the filters and the mixing chambers can be heated during the purification process, in order to increase the purification efficiency.

Fig. 5 shows a flow chart of a method 500 for producing a purification unit according to an embodiment of the present invention. The method 500 may, for example, be carried out in order to produce a purification unit described in the foregoing with reference to Figures 1 to 4. The method 500 includes a step 501 of forming a laminated composite, in particular a polymeric laminated composite, with a sample chamber for receiving the sample liquid, with a reagent chamber for receiving a reagent, with a filter device, connected or connectable to the reagent chamber via a reagent channel and to the sample chamber via a sample channel, for filtering the substance out of the sample liquid, using the reagent, with a holding device for arranging and/or holding an interchangeable collecting vessel beneath an outflow of the filter device, in order to collect the substance, and with an interface to a pressure controller for controlling a transport of liquid within the purification unit by subjecting the interface to a pneumatic pressure. With the aid of this pneumatic pressure, a part of the laminated composite, in particular a pneumatic layer, can then be depressed into the chamber (for example, reagent chamber or sample chamber) or into the channel (for example, reagent channel or sample channel) of the purification unit, as a result of which a conveying of the fluid located in this chamber, or of a liquid located in this chamber, out of the chamber is brought about. Also conceivable, however, is a blocking of a channel or the reducing of the cross section of a channel by virtue of the depressing of the pneumatic layer of the laminated composite, in order to prevent, diminish or at least render difficult a passage of liquid through this channel.

Fig. 6 shows an apparatus 600 for operating a purification unit according to an embodiment of the present invention.

The apparatus 600 includes a unit 601 which is designed to provide a signal for subjecting the interface of the purification unit to a pneumatic pressure. The apparatus 600 may serve, for example, for driving a pressure controller described further above. In this case, the apparatus 600 may, depending on the form of implementation, have been realised as a component of the pressure controller or as an external unit.

Fig. 7 shows an apparatus 700 for producing a purification unit according to an embodiment of the present invention.

The apparatus 700 exhibits a unit 701 which serves, for example, for driving, implementing and/or realising a production step in a method described with reference to Fig. 5.

The described embodiments shown in the Figures have been chosen only in exemplary manner. Differing embodiments may be combined with one another completely or with regard to individual features. One embodiment may also be supplemented by features of a further embodiment.

Furthermore, the method steps presented herein may be executed repeatedly and also in a sequence different from that described.

If an embodiment includes an 'and/or' link between a first feature and a second feature, this is to be read in such a way that the embodiment according to one form of implementation exhibits both the first feature and the second feature, and according to a further form of implementation either only the first feature or only the second feature.

Claims

Claims 1. Purification unit (100) for increasing the purity of at least one substance (124) taken from a sample liquid (122), said purification unit (100) exhibiting the following features: a sample chamber (104) for receiving the sample liquid (122); a reagent chamber (102) for receiving a reagent (120); a filter device (106), connected or connectable to the reagent chamber (102) via a reagent channel (108) and to the sample chamber (104) via a sample channel (110), for filtering the substance (124) out of the sample liquid (122), using the reagent (120); a holding device (116) for arranging and/or holding an interchangeable collecting vessel (114) at an outflow (112) of the filter device (106), in order to collect the substance (124); and an interface (118) to a pressure controller (302) for controlling a transport of liquid within the purification unit (100) by subjecting the interface (118) to a pneumatic pressure.
2. Purification unit (100) according to Claim 1, characterised by at least one sample pumping chamber (212) which is connected or connectable to the sample channel (110) and is capable of being subjected to a pneumatic pressure via the interface (118), in order to pump the sample liquid (122) through the sample channel (110).
3. Purification unit (100) according to one of the preceding claims, characterised in that the filter device (106) exhibits at least one mixing chamber (200) for mixing the sample liquid (122) and the reagent (120), and a filter (202) for filtering out the substance (124), wherein the mixing chamber (200) is connected or connectable to the reagent chamber (102) via the reagent channel (108) and to the sample chamber (104) via the sample channel (110), wherein the filter (202) is connected or connectable to the mixing chamber (200) and to the outflow (112) via an outflow channel (204), in particular wherein the outflow channel (204) exhibits at least one outflow valve (230) arranged between the filter (202) and the outflow (112).
4. Purification unit (100) according to Claims 2 and 3, characterised in that the sample pumping chamber (212) is connected or connectable, via a control channel (216), to a section of the outflow channel (204) located between the mixing chamber (200) and the filter (202), in particular wherein the control channel (216) exhibits at least one first control valve (218) and/or the sample channel (110) exhibits at least one second control valve (220), arranged between the mixing chamber (200) and the sample pumping chamber (212), for controlling a mixing circuit.
5. Purification unit (100) according to Claim 3 or 4, characterised by at least one waste container (224) which is connected or connectable, via a waste channel (226), to a section of the outflow channel (204) located between the filter (202) and the outflow (112), in particular wherein the waste channel (226) exhibits at least one waste valve (228) and/or leads into the outflow channel (204) between the filter (202) and the outflow valve (230).
6. Purification unit (100) according to one of the preceding claims, characterised by at least one reagent pumping chamber (206) which is connected or connectable to the reagent channel (108) and is capable of being subjected to a pneumatic pressure via the interface (118), in order to pump the reagent (120) through the reagent channel (108), in particular wherein the reagent channel (108) exhibits at least one reagent-chamber valve (208), arranged between the reagent chamber (102) and the reagent pumping chamber (206), and/or at least one mixing-chamber valve (210) arranged between the mixing chamber (200) and the reagent pumping chamber (206).
7. Purification unit (100) according to one of the preceding claims, characterised by at least one further reagent chamber (232, 234, 236, 238) for receiving a further reagent, wherein the filter device (106) is connected or connectable to the further reagent chamber (232, 234, 236, 238) via the reagent channel (108), in order to filter the substance (124) out of the sample liquid (122), using the further reagent.
8. Purification unit (100) according to one of the preceding claims, characterised by at least one further sample chamber (248, 266, 276) for receiving a further sample liquid, a further filter device (252, 268, 278), connected or connectable to the reagent chamber (102) via the reagent channel (108) and to the further sample chamber (248, 266, 276) via a further sample channel (250), for filtering at least one substance out of the further sample liquid, using the reagent (120), and a further holding device (258, 270, 280) for arranging and/or holding an interchangeable further collecting vessel (256, 272, 282) beneath an outflow (254) of the further filter device (252, 268, 278), in order to collect the substance.
9 Purification unit (100) according to Claims 7 and 8, characterised in that the further filter device (252, 268, 278) is connected or connectable to the further reagent chamber (232, 234, 236, 238) via the reagent channel (108), in order to filter the substance out of the further sample liquid, using the further reagent.
10. Purification apparatus (300) having the following features: at least one purification unit (100) according to one of the preceding claims; and a pressure controller (302) which has been connected to the interface (118) of the purification unit (100), in order to control a transport of liquid within the purification unit (100) by subjecting the interface (118) to a pneumatic pressure.
11. Method (400) for operating a purification unit (100) according to one of Claims 1 to 9, said method (400) including the following step: subjecting (401) the interface (118) to a pneumatic pressure by means of the pressure controller (302), in order to filter the substance (124) out of the sample liquid (122), using the reagent (120), whereby the substance (124) is collected by the collecting vessel (114).
12. Method (500) for producing a purification unit (100) for increasing the purity of at least one substance (124) taken from a sample liquid (122), said method (500) including the following step: forming (501) a laminated composite, in particular a polymeric laminated composite, with a sample chamber (104) for receiving the sample liquid (122), with a reagent chamber (102) for receiving a reagent (120), with a filter device (106), connected or connectable to the reagent chamber (102) via a reagent channel (108) and to the sample chamber (104) via a sample channel (110), for filtering the substance (124) out of the sample liquid (122), using the reagent (120), with a holding device (116) for arranging and/or holding an interchangeable collecting vessel (114) beneath an outflow (112) of the filter device (106), in order to collect the substance (124), and with an interface (118) to a pressure controller (302) for controlling a transport of liquid within the purification unit (100) by subjecting the interface (118) to a pneumatic pressure.
13. Apparatus (600, 700) which is designed to carry out, to realise and/or to drive all the steps of a method (400, 500) according to Claim 11 or 12.
14. Computer program which has been configured to carry out, to realise and/or to drive all the steps of a method according to Claim 11 or 12.
15. Machine-readable storage medium with a computer program according to Claim 14 stored thereon.
16. A purification unit substantially as herein described with reference to and as shown in the accompanying drawings.
17. Purification apparatus substantially as herein described with reference to and as shown in the accompanying drawings.
18. A method for operating a purification unit, the substantially as herein described with reference to and as shown in the accompanying drawings.
19. A computer program substantially as herein described with reference to and as shown in the accompanying drawings.
20. A machine-readable storage medium with a computer program, the medium substantially as herein described with reference to and as shown in the accompanying drawings.