WO2005075957A1

WO2005075957A1 - Microfluidic system comprising an electrode arrangement and associated control method

Info

Publication number: WO2005075957A1
Application number: PCT/EP2005/001084
Authority: WO
Inventors: Thomas Schnelle; Annette Pfennig; Torsten Müller
Original assignee: Evotec Technologies Gmbh
Priority date: 2004-02-04
Filing date: 2005-02-03
Publication date: 2005-08-18
Also published as: DE502005002217D1

Abstract

The invention relates to a microfluidic system, in particular in a cell sorter, comprising a carrier flow channel (1) which is used to supply a carrier flow having particles (2) suspended therein, a first manipulation device which is arranged in the carrier flow channel (1) and which is used to manipulate the second manipulation device which is arranged in the carrier flow channel (1) and which is used to manipulate the particles (2) suspended in the carrier flow. According to the invention, the first manipulation device and the second manipulation device comprise a common electrode arrangement (7).

Description

DESCRIPTION Microfluidic system with an electrode arrangement and associated control method

The invention relates to a microfluidic system, in particular in a particle sorter, according to the preamble of claim 1, and to a control method for an electrode arrangement in such a microfluidic system, according to the preamble of claim 20.

From MÜLLER, T. et al. : "A 3-D microelectrode system for handling and caging single cells and particles", Biosensors & Bioelectronics 14 (1999) 247-256 a microfluidic system for the investigation of biological cells is known in which the cells to be examined are suspended in a carrier stream and are manipulated and sorted dielectrophoretically. In the carrier stream, the cells to be examined are first lined up by a funnel-shaped dielectrophoretic electrode arrangement ("funnel") and then held in a dielectrophoretic cage ("cage") in order to be able to examine the cells in the cage in the quiescent state , for which microscopic, spectroscopic or fluorescence-optical measurement methods can be used. Depending on the examination of the cells trapped in the dielectrophoretic cage, these can then be sorted, for which purpose the operator controls a sorting device (“switch”) which consists of a dielectrophoretic electrode arrangement arranged downstream in the carrier stream behind the dielectrophoretic cage. In this known microfluidic system, several manipulations are therefore carried out in succession in the carrier flow channel. Arranged on devices that manipulate the suspended particles in the carrier flow.

A disadvantage of the known microfluidic system is therefore the fact that a plurality of electrodes must be arranged in the carrier current channel in order to form the various manipulation devices (e.g. "funnel", "cage" and "switch").

The invention is therefore based on the object of simplifying the known microfluidic system described above.

This task is solved by the characteristics of the subordinate claims.

The invention encompasses the general technical teaching of integrating the functions of different manipulation devices in a single electrode arrangement, so that not every manipulation device in the carrier current channel requires a separate electrode arrangement. The common electrode arrangement thus fulfills various manipulation functions (e.g. catching and sorting particles) depending on their control.

In the carrier flow channel of the microfluidic system according to the invention, therefore, at least two manipulation devices (for example a "cage" and a "switch") are preferably arranged, these two manipulation devices having a common electrode arrangement. The common electrode arrangement of the two manipulation devices can be controlled to carry out various manipulation functions. For example, the common electrode arrangement can be controlled in such a way that the current suspended particles are fixed in the electrode arrangement connected as a field cage. However, it is alternatively also possible that the common electrode arrangement is controlled in such a way that the particles suspended in the carrier stream are sorted into one of several output lines.

In the preferred embodiment, the functions of two manipulation devices are integrated in the common electrode arrangement, namely the function of a field cage and the function of a sorting device or a particle switch. However, the invention is not limited to these two functions with regard to the number of manipulation functions to be integrated in the common electrode arrangement. Rather, it is also possible to integrate other manipulation functions or a larger number of different manipulation functions in the common electrode arrangement. In particular, there is the possibility within the scope of the invention of integrating three different manipulation devices into a common electrode arrangement, the three manipulation devices being, for example, a field cage, a particle switch and a centering device (English "funnel") can act. The structure and mode of operation of these manipulation devices is described in the publication by MÜLLER, T. et al. : "A 3-D microelectrode system for handling and handling single cells and particles", the content of which is fully attributable to the present description.

Incidentally, the term manipulation device used in the context of the invention is to be understood in general and not limited to the types of manipulation devices mentioned above.

For example, the manipulation device can be a dielectric or dielectrophoretic manipulation device.

In addition, the manipulation device could dieically deform the particles (e.g. biological cells) in a conventional manner, so that the manipulation device would be referred to as a deformation device.

Furthermore, there is the possibility within the scope of the invention that the manipulation device pores the particles (e.g. biological cells), which is also known per se.

Here, the cell envelope is torn open with a high-voltage pulse, making it permeable. In this case, the manipulation device can also be referred to as an electroporation device.

However, the manipulation device in the sense of the invention can also be a device for cell fusion.

Furthermore, there is the possibility within the scope of the invention that the manipulation device thermally treats the particles or works both dielectrophoretically and electrophoretically.

The term “common electrode arrangement” used in the context of the invention should preferably be understood to mean that the common electrode arrangement has at least one electrode that is part of several different manipulation devices. It should also be mentioned that the electrode arrangement of the microfluidic system according to the invention can have a plurality of electrodes which can differ in terms of their shape, length and width.

When integrating a dielectrophoretic field cage and a dielectrophoretic particle switch in a common electrode arrangement, the common electrode arrangement is preferably arranged in a branching region of the carrier current channel in which the carrier current channel branches into a plurality of output lines. In this arrangement, the common electrode arrangement can be switched either as a particle switch or as a field cage, which would be more difficult in another arrangement upstream in the carrier flow channel. The term “branching region” of the carrier flow channel used in the context of the invention is to be understood in general and is not restricted to the intersection of the output lines, but also includes, for example, the so-called “separatrix”, which corresponds to the geometric

Intersection of the output line is upstream.

In a preferred embodiment of the invention, a separating line runs in the carrier flow channel, the particles located on one side of the separating line flowing into an output line without activating the particle switch, while the particles located on the other side of the separating line flow without activating the Flow the particle switch into the other outlet line. The particles to be sorted on the various output lines therefore only have to be brought to one side of the dividing line and then flow independently into the intended output line. This offers the advantage that the particle before it can be arranged upstream of the branching region of the output lines and in particular upstream of the geometric intersection of the output lines.

The dividing line mentioned above can be a real dividing wall which separates two partial flows from one another, the two partial flows each flowing into a specific output line. However, it is alternatively also possible that the dividing line is merely an imaginary line or area between the two partial streams.

In a variant of the invention, the particle switch is essentially arranged on the dividing line. The particle separator must therefore always be actively controlled in order to convey the respective particle into the intended output line with sufficient security.

In another variant of the invention, on the other hand, the particle line is arranged laterally next to the dividing line with respect to the direction of flow in the carrier flow channel, the particles of the particle switch preferably being supplied by an upstream centering device (“funnel”). This offers the advantage that the particle switch only has to be actively activated if a particle is to be deflected beyond the dividing line in order to get into the corresponding outlet line on the opposite side of the dividing line. If, on the other hand, a particle is to flow into the outlet line on the side of the particle switch, no active control of the particle switch is required. In this case, the particle switch can be arranged on the side of the dividing line from which the outlet line for negatively selected particles (“waste”) branches off. However, it is alternatively also possible that the par- is arranged on the side of the dividing line from which the outlet line branches off for positively selected particles.

In another exemplary embodiment of the invention, the carrier current channel does not necessarily branch into a plurality of output lines on the output side. Instead, in addition to the carrier flow channel, at least one secondary flow channel runs here, which is preferably separated from the carrier flow channel by a partition, an opening being located in the partition in which the particle separator is arranged. In this exemplary embodiment, therefore, only the individual particles are sorted, whereas the carrier streams continue to flow essentially unaffected. For example, two sidestream channels can run to the side of the carrier stream channel, which carries the carrier stream with the particles suspended therein, so that the particle switch can selectively convey the particles suspended in the carrier stream into one of the adjacent side stream channels.

In this exemplary embodiment, however, it is not absolutely necessary for a physical partition to run between the carrier flow channel and the bypass flow channel. Rather, it is also possible for the carrier flow channel to be separated from the bypass flow channel only by an imaginary separating line or separating surface, the separation of carrier flow and bypass flow being only flow-related because the carrier flow and bypass flow flow laminarly next to one another

In one exemplary embodiment of the invention, the common electrode arrangement has at least one arrow-shaped electrode and a plurality of deflection electrodes, the arrow-shaped electrode being oriented counter to the direction of flow of the carrier current, while the deflection electrodes are upstream are arranged in front of the arrow-shaped electrode and adjoin the arrow-shaped electrode. When operating as a di-electrophoretic particle switch, the arrow electrode is permanently activated, while the deflection into the different output lines takes place by switching the different deflection electrodes. This arrangement of a dielectrophoretic particle switch is also referred to as an "Ultra Fast Sorter" (UFS) and enables the suspended particles to be sorted quickly. In addition, this electrode arrangement can also be switched as a field cage in order to fix the particles suspended in the carrier stream.

In the preferred exemplary embodiments, the common electrode arrangement has six or eight electrodes which can be controlled separately in order to carry out the desired manipulation function (for example particle fixation or particle sorting). However, the invention is not limited to six or eight electrodes with regard to the number of electrodes of the common electrode arrangement, but can in principle also be implemented with other configurations.

In one embodiment of the invention, the field cage consists of eight electrodes, while the centering unit ("funnel") has four electrodes, the four upstream electrodes of the field cage being electrically connected to one of the electrodes of the centering unit. Here, a field cage and a centering unit are integrated in a common electrode arrangement, the electrodes of the centering device being controllable together with the four upstream electrodes of the field cage.

It should also be mentioned that the microfluidic system according to the invention preferably has a first measuring station. points, which examines the suspended particles in the carrier stream upstream of the common electrode arrangement in the flowing state.

This examination can concern, for example, the intensity of a fluorescence, the vitality of a cell and / or the question of whether it is a single cell or an aggregate of several cells. Furthermore, this examination can determine whether it is cells or material whose shape and size is not the primary objective of the closer examination, for example impurities or other cells, provided that they differ from the multicells. In addition to geometric parameters, material parameters can also be determined. This can be, for example, chemical concentrations which can be measured by fluorescence, but also physical parameters such as viscosity and elasticity, which can be determined by evaluating the deformations or relaxations occurring in the electrical field. In the context of this investigation, for example, a transmitted light measurement, a fluorescence measurement and / or an impedance spectroscopy can be carried out. In addition, it is possible for a transmitted light measurement to be carried out first and then a fluorescence measurement, the transmitted light measurement and the fluorescence measurement preferably being carried out in spatially separate examination windows (“region of interest”). The transmitted light measurement can, for example, differentiate between living and dead biological cells, while the fluorescence measurement can be used to examine whether the particles suspended in the carrier stream carry a fluorescence marker.

If both a transmitted light measurement and a fluorescence measurement are carried out in spatially separated examination windows as part of the preliminary examination, it is advantageous to if the examination window for the transmitted light measurement in the carrier stream is upstream of the examination window for the fluorescence measurement. However, it is alternatively also possible for the examination window for the transmitted light measurement to be arranged downstream in the carrier stream behind the examination window for the fluorescence measurement.

In the course of the examination, an optical image is preferably recorded in the first measuring station, which enables digital image evaluation to classify the particles.

The particles are preferably examined morphologically in order, for example, to be able to distinguish a single biological cell from a cell clump. However, the term optical image used in the context of the present description is to be understood generally and is not limited to two-dimensional images in the conventional sense of the word. Rather, the term “optical image” in the sense of the invention also includes a point-like or line-shaped optical scanning of the carrier stream or of the particles suspended in the carrier stream. For example, the brightness can be integrated along a line transverse to the carrier current channel in order to detect and classify individual particles.

The distinction between living and dead cells in the context of

Examination in the first measuring station can be carried out in the case of a transmitted light measurement by evaluating the intensity distribution in the recorded optical image. A special principle of this transmitted light measurement with the mentioned properties is, for example, phase contrast lighting. For example, living biological cells have a ring structure with a relatively bright edge in the transmitted light measurement and a darker center, whereas dead biological cells have an almost uniform heat in a transmitted light measurement. show lightness and appear dark against the background.

In addition to examining the particles in the first measuring station, a further measurement is preferably carried out in a second measuring station, which examines the particles fixed in the field cage. The fixation of the particles during the examination is advantageous, since a much more precise examination is possible in this way.

During the examination in the second measuring station, for example, certain molecules can be localized within a cell. For example, in the context of this investigation, molecules can be localized which are marked with a fluorescent dye.

The fluorescent dye can be, for example, molecularly produced “tags” of “green fluorescent protein” and its derivatives, other autofluorescent proteins. However, those fluorescent dyes which bind covalently or non-covalently to a cellular molecule are also suitable as fluorescent dyes. In addition, fluorescent dyes which are converted by cellular enzymes into fluorescent products or so-called FRET pairs (fluorescence resonance energy transfer) can also be used as fluorescent dyes. The state of the fluorescent dyes used can be distinguished, for example, on the basis of their spectral properties or by means of bioluminescence.

The structure and function of the molecules can also be determined on the basis of the localization of molecules within a cell. A distinction can be made here, for example, according to the occurrence in the plasma membrane, in the cytosol, in the Mitochondria, in the Golgi apparatus, in endosomes, in lysosomes, in the cell nucleus, in the spindle apparatus, in the cytoskeleton, colocalization with actin, tubulin.

Furthermore, the morphology of a cell can be determined in the course of the main and / or preliminary examination in the first or second measuring station, and dyes can also be used. In addition, two or more states of a cell population can be distinguished in the course of the main and / or preliminary examination.

Furthermore, as part of the main inspection in the second measuring station, it is possible to determine a cellular signal based on the translocation of a fluorescence-labeled molecule, e.g. Receptor activation followed by receptor

Internalization, receptor activation followed by the binding of arrestin, receptor aggregation, transition of a molecule from the plasma membrane to the cytosol, from the cytosol to the plasma membrane, from the cytosol to the cell nucleus or from the cell nucleus to the cytosol.

Furthermore, the interaction of two molecules can be determined in the course of the main and / or preliminary examination, preferably at least one of the interacting molecules carrying a fluorescent marker and the interaction e.g. is shown by colocalization-free fluorescent colors, a FRET or a change in the fluorescence lifetime.

However, the status of a cell within a cell cycle can also be determined in the course of the main and / or preliminary examination, the morphology of the cell or the staining of the cellular chromatin preferably being evaluated. A further possibility for the main and / or preliminary examination is to determine the membrane potential of a cell, preferably using membrane-sensitive dyes. Dyes which are sensitive to the plasma membrane potential and / or the itochondrial membrane potential are preferably used here.

In addition, the vitality of a cell can also be determined in the course of the main and / or preliminary examination, the morphology of the cell preferably being evaluated and / or fluorine substances being used which can differentiate between living and dead cells.

Furthermore, cytotoxic effects can also be examined during the main and / or preliminary examination and / or the intracellular pH value can be determined.

It is also possible to determine the concentration of one or more ions within a cell as part of the main and / or preliminary examination.

In the main and / or preliminary examination, an enzymatic activity within a cell can also be determined, preferably fluorine or chromogenic substances, in particular kinases, phosphatases or proteases, being used.

Furthermore, during the main and / or preliminary examination, the production performance of cells that produce biological products, such as proteins, peptides, antibodies, carbohydrates or fats, can be determined, it being possible to use one of the methods described. Finally, cell stress paths, metabolic paths, cell growth paths, cell division paths and other signal transduction paths can also be determined in the course of the main investigation in the second measuring station.

However, the invention is not limited to the above-described microfluidic system according to the invention as a single part, but also includes a device, in particular a cell sorter with such a microfluidic system as a component.

Furthermore, the invention also includes a control method for electrical control of the common electrodes in accordance with the desired manipulation function.

It should also be mentioned that the term “particle” used in the context of the invention is to be understood generally and is not restricted to individual biological cells. Rather, this term also includes synthetic or biological particles, with particular advantages if the particles contain biological materials, that is to say, for example, biological cells, cell groups, cell components, viruses or biologically relevant macromolecules, each in combination with other biological particles or synthetic carriers - Include particles. Synthetic particles can comprise solid particles, liquid particles delimited from the suspension medium or multiphase particles which form a separate phase in relation to the suspension medium in the carrier stream.

It should also be mentioned that the electrode arrangements are preferably three-dimensional arrangements. It is also possible that the electrode arrangements were only processed on one channel side. However, it is particularly advantageous to mount the electrode arrangements on two opposite channel walls to be arranged in parallel, with only one arrangement being recognizable in the drawings in the top view. For example, a "funnel" can consist of two or four electrodes.

Finally, the invention also includes the novel use of the microfluidic system according to the invention for examining and / or sorting particles, in particular biological cells.

Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred exemplary embodiments of the invention with reference to the figures. Show it:

1 shows a schematic illustration of a microfluidic system according to the invention, FIG. 2 shows another exemplary embodiment of a microfluidic system according to the invention, FIG. 3 shows another alternative exemplary embodiment of a microfluidic system according to the invention,

4 shows an alternative exemplary embodiment of a microfluidic system according to the invention, in which the sorting device is arranged upstream in front of the branching area, FIG. 5 shows another exemplary embodiment of a microfluidic system, in which the sorting device is arranged off-center in the carrier flow channel, FIG. 6 shows a microfluidic system according to the invention with three output lines FIG. 7 shows an exemplary embodiment of a microfluidic system with a central carrier flow channel which is adjacent to two bypass flow channels. 8 shows an exemplary embodiment of a common electrode arrangement which integrates the function of a field cage and a centering device, FIG. 9 shows a further exemplary embodiment according to the invention with an electrode arrangement which integrates the function of a field cage and a centering device,

Figure 10 is a schematic representation of an electrode arrangement according to the invention and Figure 11 shows another embodiment of a microfluidic system according to the invention.

The schematic illustration in FIG. 1 shows a microfluidic system with a carrier flow channel 1 for supplying a carrier flow with particles 2 suspended therein.

Arranged in the carrier flow channel 1 is a dielectrophoretic electrode arrangement 3 which centers the particles 2 in the carrier flow and lines them up one behind the other in the direction of flow. The structure and mode of operation of the electrode arrangement 3 is described, for example, in the publication by MÜLLER, T. et al. : "A 3-D microelectrode system for handling and caging single cells and particles" described, where the electrode arrangement 3 is referred to as "funnel". The content of this publication is therefore to be fully attributed to the present description with regard to the structure and mode of operation of the electrode arrangement 3.

A further dielectrophoretic electrode arrangement 4, which makes it possible to temporarily park the particles 2, is located downstream of the electrode arrangement 3 in the carrier current channel 1. The structure and mode of operation of the electrode arrangement 4 is described, for example, in MÜLLER, T. et al .: "Life cells in cell processors" (Bioworld, 2-2002), where the electrode arrangement 4 is referred to as a "hook". The content of this publication is therefore to be fully attributed to the present description with regard to the structure and mode of operation of the electrode arrangement 4, so that a detailed description of the electrode arrangement 4 can be dispensed with here.

Downstream behind the electrode arrangement 4, the carrier current channel 1 branches into two output lines 5, 6, a further electrode arrangement 7 being arranged in the branching region and which can optionally be controlled as a dielectrophoretic field cage or as a particle switch. With regard to the construction and control of the electrode arrangement 7 as a particle switch or as a field cage, reference is made to the publication by MÜLLER, T. et al. : "A 3-D microelectrode system for handling and caging single cells and particles", the content of which is fully attributable to the present description with regard to the design of the electrode arrangement 7. The electrode arrangement 7 thus combines the functions of two manipulation devices which are separate in the prior art, namely on the one hand the function of a dielectrophoretic field cage ("cage") and on the other hand the function of a particle switch ("switch"). In order to select the desired function of the electrode arrangement 7, the individual electrodes of the electrode arrangement 7 only have to be controlled accordingly, which for the individual separate manipulation devices (“cage” or “switch”) per se from the previously mentioned publication by MÜLLER, T. et al. is known. In the carrier current channel 1 there is a first measuring station 8 between the electrode arrangements 4 and 7, which carries out a preliminary examination of the particles 2 suspended in the carrier current, which preliminary examination can be carried out in the manner described at the beginning.

Depending on the result of the preliminary examination, the electrode arrangement 7 is then switched either as a field cage or as a particle switch. Initially, the electrode arrangement 7 is in the operating mode switch.

If, for example, the result of the examination in the measuring station 8 shows that the particle 2 under investigation is of no further interest, then this particle 2 is conveyed into the outlet line 5 for particles of no interest. If, on the other hand, the examination in the measuring station 8 shows that the particle 2 meets the measurement criteria of the preliminary examination, the electrode arrangement 7 is switched as a field cage, so that the particle 2 can then be examined in the fixed state in the electrode arrangement 7 by a second measuring station 9 , wherein the second measuring station 9 carries out a detailed examination of the particle 2, as was already described at the beginning. Depending on the result of the measurement at measuring station 9, the electrode arrangement 7 can then be switched as a switch (see FIG. 10 and associated description) and the particles can be transferred to one of the output lines 5 (negative), 6 (positive).

Furthermore, an electrode arrangement 10 is arranged in the output line 6 for positively selected particles 2, which centers the particles 2 in the output line β and thereby prevents the particles 2 from sinking in the output line 6. Finally, it should also be mentioned that two sheath flow lines 11, 12 open into the output line 6, which is also known per se.

The alternative exemplary embodiment shown in FIG. 2 largely corresponds to the exemplary embodiment described above and shown in FIG. 1, so that reference is made to the above description in order to avoid repetition, the same reference numerals being used for corresponding components.

A special feature of this exemplary embodiment is that the electrode arrangement 7 has only six spatially arranged electrodes, which, however, can also be switched as a field cage or as a particle switch.

Finally, the alternative exemplary embodiment shown in FIG. 3 largely coincides with the exemplary embodiment described above and shown in FIG. 1, so that to avoid repetition, reference is largely made to the above description for FIG. 1, the same reference symbols being used below for corresponding components be used.

A special feature of this exemplary embodiment is that the electrode arrangement 7 has an arrow electrode 13, which is oriented counter to the direction of flow and is permanently actuated, with two deflection electrodes adjoining the arrow electrode 13, each of which individually for deflection into the desired output line 5 or 6 can be controlled. This configuration is also known as an "Ultra Fast Sorter" (UFS) and enables the suspended particles 2 to be sorted quickly. The exemplary embodiment shown in FIG. 4 largely corresponds to the exemplary embodiments described above, so that to avoid repetition, reference is largely made to the above description, the same reference numerals being used for corresponding components and only the special features of this exemplary embodiment being described.

A special feature of this exemplary embodiment is that the electrode arrangement 7 is arranged in the carrier current channel 1 upstream in front of the branching region of the two output lines 5, 6. A flat dividing line 14 runs in the middle in the carrier flow channel 1, particles 15 shown in black in the drawing flowing into the outlet line 5 for negatively selected particles, whereas particles 16 shown in an outline in the drawing flow into the other outlet line 6 for positively selected particles , The dividing line 14 is also referred to as a separatrix and separates two partial flows in the carrier flow channel 1, which flow as particle separators into the respectively associated upper and lower output lines 5 and 6 without triggering the electrode arrangement 7. To achieve a defined sorting of the particles 15, 16 on the two output lines 5, 6, the common electrode arrangement 7 must therefore always be actively activated as a particle switch.

The alternative exemplary embodiment of a microfluidic system shown in FIG. 5 largely corresponds to the exemplary embodiment described above and shown in FIG. 4, so that reference is largely made to the above description and the same reference numerals are used below for corresponding components. A special feature of this exemplary embodiment is that the common electrode arrangement 7, which can optionally be controlled as a particle switch or as a field cage, is arranged off-center in the carrier current channel 1. This means that the electrode arrangement 7 is located laterally next to the dividing line 14 on the side of the output line 6 with respect to the flow direction in the carrier flow channel 1. This means that the particles 15, 16 flow independently into the output line 6 if the electrode arrangement 7 is not actively activated as a particle switch in order to deflect the particles 15 beyond the dividing line 14 to the other side of the carrier flow channel 1. This exemplary embodiment is therefore advantageous if the proportion of the particles 15 to be selected negatively is significantly smaller than the proportion of the particles 16 to be selected positively, since the electrode arrangement 7 is actuated only to sort out the relatively small number of the particles 15 to be selected negatively is required.

FIG. 6 shows a further exemplary embodiment of a microfluidic system with a carrier flow channel 17 for supplying a carrier flow with particles 18, 19, 20 suspended therein, the particles 18, 19, 20 differing, which is shown in the drawing by the different graphic representation of the Particles 18, 19, 20 is indicated.

The carrier flow channel 17 branches downstream into three output lines 21, 22, 23 for receiving and discharging the different particles 18, 19, 20. The output line 21 serves here for receiving the black particles 20, while the output line 22 for removing the Hatched particles 19 is used, whereas the output lines device 23 picks up and removes the particles 18 drawn as an outline.

In this case, two (imaginary) separating surfaces or planar separating lines 24, 25 run in the carrier flow channel 17, which in the

Tragerstromkanal 17 delimit three substreams and form the dividing lines 24, 25 in the view shown.

The particles suspended in the upper partial flow above the dividing line 24 automatically reach the outlet line 21, provided that these particles are not actively deflected, as will be described in detail below.

The particles, which are suspended in the carrier flow between the two separating lines 24, 25, on the other hand, reach the output line 22 independently without external deflection.

Furthermore, the particles suspended in the carrier stream below the dividing line 25 flow independently into the outlet line 23, provided that these particles are not actively deflected, as will be described in detail below.

In the carrier flow channel 17 there is initially a centering device 26 which lines up the particles 18, 19, 20 suspended in the carrier flow on the dividing line 25 and feeds them to a subsequent electrode arrangement 27. The electrode arrangement 27 combines the function of a field cage with the function of a deflection device ("switch").

When actuated as a field cage, the electrode arrangement 27 can fix the particles 18, 19 or 20 so that the particles 18, 19 or 20 are examined by a measuring station, which is not shown for the sake of simplicity. When actuated as a particle switch or deflection device, on the other hand, depending on the result of the previous examination, the electrode arrangement 27 can either let the particles 18, 19 or 20 flow straight on or laterally into the partial flow between the two dividing lines 24, 25 distract.

Downstream of the electrode arrangement 27 there is a further centering device 28 which is arranged off-center in the carrier flow channel 17 and which lines up the particles suspended in the two partial flows on both sides of the dividing line 24 on the dividing line 24 and feeds them to a further electrode arrangement 29, optionally as a field cage or can be controlled as a particle switch.

When the electrode arrangement 29 is activated as a field cage, the electrode arrangement 29 can fix the particles 19 or 20 so that they can be examined by a measuring station, which is not shown for the sake of simplicity.

When activated as a particle switch, the electrode arrangement can either deflect the particles into the partial stream located above the dividing line 24 or into the partial stream located below the dividing line 24, so that the particles flow into the desired outlet line 21 or 22. The electrode arrangement 29 is activated as a particle switch for sorting the particles onto the two output lines 21, 22 in this case as a function of the result of the previous examination of the measuring station (not shown).

As in FIG. 9, the electrode arrangements 27, 29 can additionally function as the center Riereinrichtung 26, 28 take over, with which these upstream elements can be omitted.

FIG. 7 shows a side view of a further exemplary embodiment of a microfluidic system with a carrier flow channel 30 and two adjacent side flow channels 31, 32, the two side flow channels 31, 32 being separated from the carrier flow channel 30 by a partition wall 33, 34 in each case.

Suspended particles 35, 36, 37 are supplied to the microfluidic system via the carrier flow channel 30, the particles 35, 36, 37 differing and being correspondingly distributed over the two secondary flow channels 31, 32 or over the continuing carrier flow channel 30.

An electrode arrangement 38 is initially located in the carrier flow channel 30 at its upstream end in order to line up the particles 35, 36, 37 in the center in the carrier flow channel 30.

Downstream behind the electrode arrangement 38, the partition walls 33, 34 each have an opening through which the particles 36, 37 can be deflected into the adjacent bypass channels 31, 32. For this purpose, an electrode arrangement is arranged in the area of the openings, which can be controlled either as a field cage or as a particle switch, the common electrode arrangement consisting of eight electrodes, of which only four electrodes 39, 40, 41, 42 can be seen here.

When the common electrode arrangement is actuated as a field cage, the particles 35, 36 and 37 can be fixed in the field cage in order to carry out a detailed examination by To enable measuring station, which is not shown for simplicity.

Depending on the result of this examination, the common electrode arrangement can then be actuated as a particle switch in order to convey the particles 37 into the bypass duct 31 and to deflect the particles 36 into the bypass duct 32.

In addition, as described in FIG. 1, the particles can also be directed into different flow paths (in the plane shown and in front or behind) of the channels 30, 31 and 32 by the eight-electrode arrangement and thus address up to 9 different fluidic outputs (for fractionation) become.

The exemplary embodiment of a microfluidic system shown in FIG. 8 largely corresponds to the exemplary embodiment described above and shown in FIG. 4, so that to avoid repetition, reference is largely made to the above description and the same reference numerals are used for corresponding components.

A special feature of this exemplary embodiment is that the functions of the electrode arrangements 3 and 7 in FIG. 4 in this exemplary embodiment are integrated in a single electrode arrangement 43, the electrode arrangement 43 optionally as a centering device ("funnel"), as a field cage (" field cage ") or as a particle switch.

The electrode arrangement 43 in this case has electrodes which converge towards one another in the direction of flow, the end tips of these electrodes being convex, for example semicircular in shape are. With the help of this special design, the electrode arrangement 43 can also hold particles.

Furthermore, FIG. 9 shows a schematic illustration of a common electrode arrangement, which can be controlled either as a centering device or as a field cage. For this purpose, the electrode arrangement has eight rectangular cage electrodes, only four cage electrodes 44, 45, 46, 47 being recognizable in the top view.

Furthermore, four conventionally arranged deflection electrodes are provided, only two deflection electrodes 48, 49 being visible in the top view.

The upstream cage electrodes 45, 47 are each electrically connected to one of the two deflection electrodes 48, 49 and can be controlled together with them.

Potential control options for the electrode arrangement shown in FIG. 9, in particular red, AC I and AC II mode, are listed in Table 1.

Red and AC I mode are suitable both for catching the particles in the field cage and for lining up the particles. The red mode has the advantage that it prevents the particles from entering the cage much more effectively than the AC I mode.

In an alternative embodiment of the electrode arrangement shown in FIG. 9, one of the electrodes (pairs) 49 or 48 is extended at the downstream tip and is designed as a hook over the central line. The other pair of electrodes is offset upstream or can also be omitted in a further possible embodiment. In addition, in the red and AC I modes, an intermediate Realize storing the particles in front of the actual cage.

The AC II mode is characterized by a particularly stable holding (without rotation) of the particles and is therefore particularly suitable for high-resolution measurements.

In order to implement a provision of the particles in this mode, the following arrangement must be used: one electrode each of the described pair of electrodes (48, 49) is elongated in hook-like manner in different planes. This ensures a hook function in the Red and AC II modes. If the line-up function can be dispensed with, the shorter straight counter electrode (48, 49) can be dispensed with in this embodiment.

Finally, FIG. 10 shows a schematic representation of the geometric arrangement of eight cage electrodes 50, 50 ', 51, 51', 52, 52 ', 53, 53', the flow direction running in the Y direction.

The electrical control of the individual cage electrodes 50, 50 ', 51, 51', 52, 52 ', 53, 53' is described, for example, in the publication by MÜLLER, T. et al. : "A 3-D microelectrode system for handling and caging single cells and particles" described, the content of which is fully to be attributed to the present description. In order to let a trapped particle in the Y direction, the cage electrodes 52, 52 ', 53, 53' are weakened sufficiently, which can be done, for example, by switching these cage electrodes off. The same applies to the X or Y direction. A weakening of the electrodes 52, 52 'leads to the escape of the captured particle in the XY direction (1, 1, O direction). If, on the other hand, only the electrode 52 'is weakens, the captured particle leaves the field cage in the 1, 1, 1 direction. A particularly rapid particle escape (catapult mode) can be achieved by increasing the voltage on at least one further electrode (for example the opposite electrode) and / or changing the phase position.

In an analogous manner, a particle can also be let into the cage in a defined manner, or run through defined trajectories, with which switch functions of the cage can also be realized. This is described as an example below. The control types known from MÜLLER, T. et al .: “A 3-D microelectrode system for handling and caging single cells and particles” include rotation and AC field modes, which are shown in Table 1 with reference to the electrode designations are shown in Figure 10. These modes can trap particles in the cage and release them in a defined direction, as described above. Furthermore, switch modes are given as examples, which deflect particles that flow in from the y direction into the xy direction or xy direction.

Table 1: Exemplary phase positions for control modes of an octode field cage

Finally, FIG. 11 shows a further exemplary embodiment of a microfluidic system according to the invention, a carrier stream with particles suspended therein flowing in the direction of the arrow.

In the upstream region of the microfluidic system, several funnel-shaped electrodes 54, 55 are initially arranged, which center the particles suspended in the carrier flow on a center line 56.

Downstream of the electrodes 54, 55 there is an electrode arrangement 57, which is used to capture the particles and to switch quickly in two flow paths. The electrode arrangement 57 has at its upstream end a field cage which consists of a plurality of electrodes 58-61. Furthermore, the electrode arrangement 57 has a plurality of deflection electrodes 62, 63 on both sides of the center line 56, which deflect the particles into one of two flow paths when appropriately controlled. The deflection electrodes 62, 63 are in this case galvanically connected to the electrodes 58, 61 of the field cage.

The invention is not restricted to the preferred exemplary embodiments described above. Rather, a large number of variants and modifications are possible which also make use of the inventive idea and therefore fall within the scope of protection. Reference symbol list: ι carrier current channel 44 cage electrode

2 particles 45 cage electrode 3 electrode arrangement 46 cage electrode 4 electrode arrangement 47 cage electrode 5 output line 48 deflection electrode 6 output line 49 deflection electrode 7 electrode arrangement 50, 50 'cage electrode measuring station 51, 51' cage electrode

9 measuring station 52, 52 'cage electrode

10 electrode arrangement 53, 53 'cage electrode

11 Envelope power line 54, 55 electrodes

12 Envelope power line 56 center line

13 arrow electrode 57 electrode arrangement

14 dividing line 58-61 electrodes

15 particles 62, 63 deflection electrodes

16 particles

17 carrier current channel

18 particles

19 particles

20 particles

21 output line

22 output line

23 output line

24 dividing line

25 dividing line

26 centering device

27 electrode arrangement

28 centering device

29 electrode arrangement

30 carrier current channel

31 bypass duct

32 bypass duct

33 partition

34 partition

35 particles

36 particles

37 particles

38 Electrode arrangement

39 electrode

40 electrode

41 electrode

42 electrode

43 electrode arrangement

Claims

EXPECTATIONS

1. Microfluidic system, especially in a particle sorter, with

- at least one carrier flow channel (1) for supplying a carrier stream with particles (2) suspended therein, - a first manipulation device arranged in the carrier flow channel (1) for manipulating the particles (2) suspended in the carrier stream,

- A second manipulation device arranged in the carrier flow channel (1) for manipulating the particles (2) suspended in the carrier flow, characterized in that the first manipulation device and the second manipulation device have a common electrode arrangement (7).

2. Microfluidic system according to claim 1, characterized in that the common electrode arrangement additionally forms a third manipulation device.

3. Microfluidic system according to one of the preceding

Claims, characterized in that the common electrode arrangement (7) has at least one electrode which is both part of the first manipulation device and part of the second manipulation device.

4. Microfluidic system according to one of the preceding claims, characterized in that the first manipulation device is a field cage which fixes the particles (2).

5. Microfluidic system according to one of the preceding claims, characterized in that the second manipulation device is a particle filter.

6. Microfluidic system according to one of the preceding claims, characterized in that the second or the third manipulation device is a centering device which centers the particles in the carrier flow channel.

7. Microfluidic system according to one of the preceding claims, characterized in that the carrier flow channel (1) branches into a plurality of output lines (5, 6) in a branching area.

8. Microfluidic system according to claim 7, characterized in that the common electrode arrangement (7) is arranged in front of or in the branching area.

9. -Microfluidic system according to claim 7 or 8, characterized in that a separating line (14) runs in the carrier flow channel, the particles (15) located on one side of the separating line (14) without activating the particle switch (7) in which flow an output line (5), while the particles (16) located on the other side of the dividing line (14) flow into the other output line (6) without activating the particle switch (7).

10. Microfluidic system according to claim 9, characterized in that the particle switch (7) is arranged essentially on the separating surface (14).

11. Microfluidic system according to claim 9, characterized in that the particle switch is arranged laterally next to the dividing line.

12. Microfluidic system according to one of the preceding claims, characterized in that in addition to the carrier flow channel (30) at least one secondary flow channel (31, 32) runs, which is separated from the carrier flow channel (30) by a partition (33, 34), wherein there is an opening in the partition (33, 34) in which the particle separator (39-42) is arranged.

13. Microfluidic system according to one of the preceding claims, characterized in that the electrode arrangement (7) has at least one arrow-shaped electrode (13) and a plurality of deflection electrodes, the arrow-shaped electrode (13) being oriented counter to the flow direction of the carrier current, while the Deflection electrodes are arranged upstream of the arrow-shaped electrode (13) and adjoin the arrow-shaped electrode (13).

14. Microfluidic system according to one of the preceding claims, characterized in that the electrode arrangement (7) has four, six or eight separately controllable electrodes.

15. Microfluidic system according to one of the preceding claims, characterized in that the field cage has eight electrodes (44-47), while the centering unit (48, 49) has four electrodes, the four upstream electrodes (45, 46) of the field cage are electrically connected to one of the electrodes (48, 49) of the centering unit.

16. Microfluidic system according to one of the preceding claims, characterized by a first measuring station (8) which examines the suspended particles in the carrier stream (2) upstream in front of the common electrode arrangement (7) in the flowing state.

17. Microfluidic system according to one of the preceding claims, characterized by a second measuring station (9) which examines the particles (2) fixed in the field cage.

18. Microfluidic system according to one of the preceding claims, characterized by a control unit for controlling the common electrode arrangement, the control unit being connected on the input side to the first measuring station and / or the second measuring station and the common electrode arrangement depending on the examination in the first measuring station and / or controls the second measuring station.

19. Particle sorter with a microfluidic system according to one of the preceding claims.

20. Control method for an electrode arrangement (7) which is arranged in a carrier current channel (1) of a microfluidic system, a carrier current with particles (2) suspended therein flowing in the carrier current channel (1), while the electrode arrangement (7) is thus electrically controlled is that the particles (2) suspended in the carrier stream are subjected to a first manipulation by the electrode arrangement (7), characterized in that the electrode arrangement (7) is optionally used to carry out the first manipulation tion on the particles (2) or to carry out a second manipulation on the particles (2).

21. Control method according to claim 20, characterized in that the first manipulation comprises fixing the suspended particles (2), while the second manipulation comprises sorting the suspended particles (2).

22. Control method according to one of claims 20 to 21, characterized in that the particles (2) suspended in the carrier stream are examined.

23. Control method according to claim 22, characterized in that the electrode arrangement (7) is controlled as a function of the examination of the particles (2) for carrying out the first manipulation and / or the second manipulation.

24. Use of a microfluidic system according to one of claims 1 to 18 for examining and / or sorting particles, in particular biological cells. - -k -k ~ k -k