GB2499727A - Chip calorimeter for determining the effect of nanoparticle materials on living cells - Google Patents
Chip calorimeter for determining the effect of nanoparticle materials on living cells Download PDFInfo
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- GB2499727A GB2499727A GB201303107A GB201303107A GB2499727A GB 2499727 A GB2499727 A GB 2499727A GB 201303107 A GB201303107 A GB 201303107A GB 201303107 A GB201303107 A GB 201303107A GB 2499727 A GB2499727 A GB 2499727A
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- Prior art keywords
- bead
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- cells
- test chamber
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/5005—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells
- G01N33/5008—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics
- G01N33/5014—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving human or animal cells for testing or evaluating the effect of chemical or biological compounds, e.g. drugs, cosmetics for testing toxicity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K17/00—Measuring quantity of heat
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
- G01N25/48—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
- G01N25/48—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation
- G01N25/4873—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation for a flowing, e.g. gas sample
- G01N25/488—Details
Abstract
A chip calorimeter 40 comprises through-flow test chamber 11 with test channel 47, supply channel 12 for the supply of magnetic-bead samples 16 prepared with living cells and nanoparticle material, drainage channel 13, transport fluid 17, permanent magnet 18 positioned on the surface 19 of chamber 11 which engages its magnetic field in the test chamber, pivot device 20 holding the magnet and moving it away from the chamber, and at least one thermopile 24-27 in contact with the test chamber, a holding device 14 to suspend the test chamber vertically, pump unit 28 for fluid drainage, bead-sample trap 29, wherein thermal power measurement is implemented on the bead sample 16 fixed magnetically in chamber 11 after settling of thermal disturbances of the samples, wherein the thermal power produced by the cells is converted in the thermopiles into electrical signals which are processed in evaluation device 39 which reproduce the response of the living cells to contact with nanoparticles on the basis of the measured thermal power produced by the cells.
Description
1
A DEVICE AND A METHOD FOR DETERMINING THE EFFECT OF NANOPARTICLE MATERIALS ON LIVING CELLS BY MEASURING THE THERMAL POWER PRODUCED BY THE CELLS BY MEANS OF A CHIP CALORIMETER
5
Description
The invention relates to a device and a method for determining the effect of nanoparticle materials on living cells by measuring the thermal power produced by the cells by means of a chip calorimeter.
10
The use of anthropogenically generated nanoparticle materials in technical products, in pharmaceutical preparations and in many household goods, paints and dyes, car tyres and diesel fuel is increasing. At the same time, however, this industrial production and distribution is also associated with risks, which, in many cases, cannot 15 yet be assessed. One of the reasons for this uncertainty is that, especially, the toxic effect of these innovative nanoparticle materials on living cells has, in many cases, not been investigated. In particular, there is so far no deep understanding of the toxic effect at the molecular level. Accordingly, a targeted testing of the toxic effect based on investigations of influence on given portions of the effect chain of nanoparticle 20 materials is required.
Calorimetry, by means of which the thermal power of biochemical activities can be determined, presents such a method for determining the effect of a test substance on the physiological condition of a living cell.
25
It is estimated that a microbial cell produces approximately 3 pW to 4 pW thermal power during the growth phase. Accordingly, the use of, for example, 104 cells (for example, in 6 jxL volume) leads to 30 nW to 40 nW thermal power, which is disposed within the frame of the measurement resolution (<100nW) for chip calorimetry.
30
One advantage of chip calorimetry is the possibility of investigating biofilms. Unicellular organisms, especially prokaryotic cells, often live, in their natural environment, in the form of a biofilm - an aggregate of many cells (including cells of different species), which are surrounded by a layer consisting primarily of
2
polysaccharides. Investigating damage to these biofilms is currently possible only in a relatively labour-intensive and cost-intensive manner.
The fact that biofilms are of great importance not only in environmental microbiology 5 but also in the clinical field - for example, pathogenic types of microorganisms form biofilms with open wounds or deposits on artificial joints and catheters - underlines the value of chip calorimetry as a test method.
A chip calorimeter with a test chamber with a through-flow of liquids and with a 10 sample aggregate disposed in it is described in document DE 10 2008 Oil 839 B4, in which a miniaturisation of the calorimetry has provided a rapid test method at the same time as increasing measurement sensitivity.
The conventional, horizontally arranged chip calorimeter 1 illustrated in Figure 1 15 provides a chip carrier 2, a chip 3 attached to it, with a chip membrane with the test chamber 4, which can be charged with chemical or biological sample aggregates to be measured with regard to thermal power, disposed on it, on the chamber base of which a flow channel 5 open towards the base is introduced to allow thermal transfer in the direction towards the chip membrane, which is fitted with a thermopile arrangement 6 20 disposed below it, which is connected to the chamber base in a thermally transmissive manner.
In this context, a covering foil 7 is attached to the base of the test chamber 4 in order to close the flow channel 5, which is open at the base, wherein the covering foil 7 is 25 disposed between the chamber base and the chip membrane for the spatial separation of the test chamber 4 and the chip 3, and connected in a detachable manner to the chip membrane by means of a controllable holding device 8, which engages with the test chamber 4.
30 The test chamber 4 prepared with the fixed sample aggregate can be attached in a reversible manner to the chip 3, since the holding device 8 holds the test chamber 4 at its upper side and presses it onto the chip membrane. The fluid 9 is transported through at least one supply tube into the test chamber 4 and, after flowing through the test chamber 4 leaves the test chamber 4 through at least one outlet tube. During the 35 dwell-time of the fluid 9 in the test chamber 4, the flowing liquid 9 is flushed over the
3
sample aggregate. In this context, a thermal transfer takes place from the test chamber 4 towards the thermopile arrangement 6 comprising several thermopiles TP1, TP2, TP3 and TP4 which register the thermal power.
5 As a result of the provision of the covering foil 7, the chemical and/or biological sample aggregates can be prepared in a store by implementing them in the test chambers 4 provided.
One problem in this context is that, in the case of a thermal power measurement with 10 many sample aggregates, which can also be beads, for example, with bacteria cultivated on them as bead samples, the test chamber 4 must be removed from the chip calorimeter 1 for every test run, in order to fix a bead sample in it. In spite of the miniaturisation of the test chamber 4 and the component groups associated with the conventional chip calorimeter 1, the test procedures for the implementation of every 15 thermal-power measurement last a relatively long time as a result of the frequent replacement of the test chamber 4.
The invention is therefore based upon the object of specifying a device and a method for determining the effect of nanoparticle materials on living cells by measuring the 20 thermal power produced by the cells by means of a chip calorimeter, which are embodied in an appropriate manner for measuring the thermal power transferable from the sample aggregate comprising magnetic beads at least with living cells attached to them, to at least one of the thermopiles in a simplified, faster and more accurate manner and, from this, to determine the effect of the material of nanoparticles 25 contacting the cells on the living cells in a shorter time. Moreover, time-consuming replacements of the test chamber should be avoided.
The object is achieved by the features of claims 1 and 16. The device for determining the effect of nanoparticle materials on living cells by measuring the thermal power 30 produced by the cells by means of chip calorimeter contains at least the following: as the chip calorimeter:
- a through-flow test chamber with a test channel and with a supply channel for the supply of magnetic-bead samples with producing thermal power and prepared with living cells brought into contact with at least one nanoparticle material and with a
4
drainage channel for the bead samples and a transport fluid provided for the transport of bead samples,
- a permanent magnet, which is positioned on the surface of the through-flow test chamber and which engages through the through-flow test chamber with its magnetic
5 field strength,
- a pivot device holding the permanent magnet, wherein the pivoting of the permanent magnet takes place away from the surface up to a specified spacing distance from the surface and back again, and
- at least one thermopile, which is in contact with the surface of the through-flow test 10 chamber arranged opposite to the permanent magnet,
wherein, moreover, the following are allocated to the device:
- a holding device, on which the through-flow test chamber is suspended vertically at least by the supply channel and/or the drainage channel,
- a pump unit, which is arranged downstream of the drainage channel and used for a 15 targeted drainage of the transport fluid,
and
- a bead-sample trap, which is connected to the pump unit and in which the bead samples are stored,
wherein the thermal-power measurement is implemented in the chip calorimeter on the 20 bead sample magnetically fixed in the through-flow test chamber after the settling of the thermal disturbances triggered by the transport of the bead samples, wherein the thermal power produced by the cells is converted into electrical signals in at least one of the thermopiles, wherein the thermopiles are connected to an evaluation device via signal lines and communicate the electrical signals to the evaluation device, and 25 wherein the electrical signals are processed to form displays in the evaluation device containing a computer by means of computer-software technology and technical and biological algorithms, which reproduce the response of the living cells to the contact with the material of the nanoparticles on the basis of the measured thermal power produced by the cells.
30
The effect with regard to the different response of the living cells, primarily through the production of different material-related thermal power, is specified in the form of different electrical signals. These signals evaluated by means of computer-software technology and technical and biological algorithms can be used in displays for further 35 interpretation, especially of the effect.
5
The displays can be output by the evaluation device as information or data, for example, in tabular form and/or in the form of a curve.
The chip calorimeter for measuring the thermal power of magnetic samples can 5 comprise at least:
- a through-flow test chamber with a test channel and with a supply channel for the supply of samples and with a drainage channel for the samples, in which a transport of the samples is implemented by means of a transport fluid via a pump unit connected to the drainage channel,
10 - at least one thermopile for registering the thermal power and converting it into electrical signals,
- an evaluation unit connected via signal lines to the thermopiles, which evaluates the electrical signals by means of specified computer-software technology,
wherein, according to the invention 15 the test channel of the through-flow test chamber is orientated vertically, and, furthermore, the following are provided:
- a permanent magnet, which is positioned on the surface of the through-flow test chamber and engages with its magnetic field strength in the through-flow test chamber and is used for fixing the magnetic samples,
20 a pivot device holding the permanent magnet, wherein the pivoting of the permanent magnet is takes place away from the surface up to a specified spacing distance from the surface and back again in order to cancel the fixing of the magnetic samples, and wherein at least one thermopile is disposed in contact with the through-flow test chamber arranged opposite to the permanent magnet in order to register the thermal 25 power of the magnetic sample.
The chip calorimeter can be embedded in a thermostat, to which the through-flow test chamber is thermally coupled and which achieves a partial thermostatting of the transport fluid used for the transport of the magnetic-bead samples.
30
Before introduction into the supply channel, a magnetic-bead sample for the implementation of the measurements can comprise at least un-prepared magnetic beads, magnetic beads prepared with living cells, magnetic beads prepared with living cells already contacted with nanoparticles, or magnetic beads prepared with living 35 cells still to be contacted with nanoparticles.
6
The magnetic-bead samples made from un-prepared magnetic beads or magnetic beads prepared with living cells are used substantially for comparison measurements with the magnetic-bead samples made from magnetic beads prepared with cells already contacted with nanoparticles. In the latter case, the nanoparticles are also disposed on 5 the magnetic bead.
Accordingly, a bead sample can comprise magnetic beads with adsorbed living cells applied to their surface, which have optionally had a contact treatment for a defined time with nanoparticles or which have had no contact treatment with nanoparticles 10 before flushing into the through-flow test chamber, wherein the influence of the material of the nanoparticles on the living cells can change their metabolic thermal power.
The magnetic beads used can be composed of several individual particles made from 15 super-paramagnetic iron oxide (y-Fe203) and provide a bead-like shape or a dropletlike shape of an agglomeration, which is surrounded by a protective coating. The agglomeration can be coated with polyethylene imine as ligand, which represents a strong non-specific anionic exchanger. The magnetic beads used for the measurements can be 0.5 |xm to 300 |xm in size.
20
The supply channel and the drainage channel (bead-sample transport channels) represent cannulas and can be realised as steel capillaries.
The pivot device can contain a spring attached between the permanent magnet and the 25 holding device, especially a plate spring, and a filament attached to the spring, wherein the filament is used to deflect the spring, and therefore the permanent magnet, away from the surface of the through-flow test chamber.
Alongside the spring attached between the permanent magnet and the holding device, 30 the pivot device can, however, also provide a displaceable sliding magnet corresponding with the permanent magnet, which can lift the permanent magnet from the surface of the through-flow test chamber by means of pivoting, that is, by means of its mobility within the plane and in the direction towards the permanent magnet, and guide it out of its active magnetic range with regard to the through-flow test
7
chamber and respectively back towards the surface again dependent upon the re-polarisation of the sliding magnet.
The bead-sample trap which is attached to the pump unit provides at least one magnet, 5 which filters the magnetic-bead samples out of the flowing liquid and accumulates them on itself.
A T-piece can be attached between the pump unit and the bead-sample trap, at the branching of which a syringe is attached, with which a cleaning fluid can be guided 10 into the bead-sample trap in order to clean it.
In the region of the holding device, a temperature sensor can be attached in contact with the supply channel.
15 A funnel for filling transport fluid with the prepared bead sample disposed in it into the supply channel can be allocated to the supply channel.
In the method for determining the effect of the nanoparticle materials on living cells by measuring the thermal power produced by the cells with the use of a device 20 including a chip calorimeter according to the characterising part of claim 16, comparison measurements are implemented respectively between magnetic-bead samples prepared with living cells with regard to the thermal power produced by the living cells with reference to the presence or non-presence of a time-defined contact between the respective cell structure and the material of the specified nanoparticles 25 under investigation, wherein the contact either took place at a defined time before the flushing of prepared magnetic-bead samples into the through-flow test chamber or takes place continuously during the passage through the through-flow test chamber, wherein the comparison measurements are evaluated by an evaluation device.
30 A contact treatment between the magnetic beads and the living cells adsorbed on them and the nanoparticles both with different concentrations of the nanoparticles and also taking into consideration the concentration ratio between living cells and nanoparticles is implemented dependent upon the specified evaluation modality.
8
By means of a computer allocated to the evaluation device, a display of the cytotoxic effect of the nanoparticle materials is provided through the calorimetric detection of the heat produced by the biological objects in the form of a metabolic thermal power and its variation resulting from the effect of the nanoparticle materials,
5 wherein, with regard to the cells/objects under investigation, it is provided that the thermal power of the cells is measured in cultures, wherein:
- the cultures are present in the form of a biofilm or are immobilised by coupling via antibody-antigen interaction or electrostatically on magnetic beads or
- the cultures comprise one (clonal) cell type or several (mixed culture) cell types or 10 - the cells under test are of prokaryotic or eukaryotic origin or
- the cells under test are naturally occurring cells or cells modified by genetic technology or
- the cells under test are artificially sustained cell cultures (e.g. He-La cells).
15 When testing the effect of the material of nanoparticles on microorganisms, microorganisms are used in the form of biofilms, which are cultivated on the magnetic beads as bead samples, wherein the microorganisms cultivated on the bead samples by biofilm formation represent realistic models for assessing the cytotoxic effect of nanoparticle materials in the 20 environment because of the high degree of heterogeneity, and a cultivation of the biofilms on the magnetic-bead samples allows an automated bead-sample transfer by the chip calorimeter.
The method of functioning of the device according to the invention is explained in 25 greater detail below:
The through-flow test chamber is provided with a vertically arranged channel for supply and a vertically arranged channel for the drainage (bead-sample transport channels) of at least one prepared magnetic-bead sample.
30
The through-flow test chamber is suspended on cannulas, which realise the bead-sample transport channels, within a holding device, which is thermally coupled to the thermostat of the chip calorimeter and achieves a partial thermostatting of the transport fluid required for the transport of the bead-samples.
35
9
The permanent magnet is pressed onto the surface of the through-flow test chamber via a spring.
For the introduction of a bead sample, the latter is flushed into the through-flow test 5 chamber by means of the flow of transport fluid (e.g. water or culture medium) and held at the height/level of the permanent magnet.
The measurement of the thermal power produced by the cells of the bead sample in the test channel is implemented on the bead sample disposed and fixed at the positional 10 level of the permanent magnet after the settling of the thermal disturbances triggered by the transport of the bead samples in at least one thermopile also attached to the surface of the through-flow test chamber.
The measured thermal power is converted into electrical signals and supplied to an 15 evaluation device.
After the completion of the measurement, the permanent magnet is lifted by means of a pivot device, in which, for example, a spring is deflected mechanically via the thin filament, and the bead samples are flushed out of the test channel of the through-flow 20 test chamber by means of the fluid flow and captured outside the chip calorimeter in a bead-sample trap.
While, in the case of a measurement using one thermopile of the thermal power produced, the absolute voltage values are measured with additional subliminal 25 disturbance values, the advantage of measuring the thermal power produced with at least two thermopiles consists in the fact that the disturbance values are eliminated by the difference formation between the two thermopile voltage values.
With the evaluation device, which processes the electrical signals by means of its 30 computer-software technology and technical and biological algorithms, the device according to the invention can be used to analyse the effect, also referred to as a toxic effect, of the material of nanoparticles on microbial test systems (plankton cultures, biofilm) and also on eukaryotic cell cultures, provided these are immobilised on magnetic beads. In the latter case, the method can be used to investigate the toxic 35 effect on healthy living cells and also for the evaluation of the use of nanoparticle
10
materials in the treatment of living, pathological cells, for example, for the treatment of tumour cells.
As a result of the development of the device according to the invention for the 5 implementation of chip calorimetry, the use of the device described here is particularly suitable for the purposes named above, especially for the (rapid and cost-favourable) screening of new nanoparticle materials.
Further developments and advantageous embodiments of the invention are specified in 10 the other dependent claims.
The invention is explained in greater detail on the basis of an exemplary embodiment with reference to several drawings.
15 The drawings are as follows:
Figure 1 a schematic view of a chip calorimeter according to the prior art;
Figure 2 an enlarged schematic view of the test chamber according to Figure 1;
20
Figure 3 a schematic view of a device according to the invention with a chip calorimeter according to the invention;
Figure 4a an enlarged detail of the measurement region with test channel during 25 the filling of a magnetic-bead sample prepared with cells into the supply channel according to Figure 3;
Figure 4b an enlarged detail of the measurement region with test channel at the moment of measuring the thermal power of the magnetically fixed magnetic-30 bead sample prepared with cells; and
Figure 4c an enlarged detail of the measurement region with test channel during the flushing of the magnetically fixed, magnetic-bead sample prepared with cells out of the through-flow test chamber of the chip calorimeter and with the 35 pivoting away of the permanent magnet;
11
Figure 5a a typical characteristic of the thermo-voltage, that is to say, a characteristic of the thermo-voltage with a cyclical dosage of water;
Figure 5b a typical characteristic of the temperature, measured by the 5 temperature sensor, on the holding device, that is, the temperature rise in the copper holding device;
Figure 5c a typical characteristic of the control power of the internal thermostat, that is, a characteristic of the decline of the heating power during dosage;
10
Figure 6a a measurement curve for the thermo-voltage in the case of a measurement of 5 • 106 cfu in the test channel;
Figure 6b a measurement curve for the thermo-voltage in the case of a 15 measurement of 5 • 105 in the test channel; and
Figure 6c a measurement curve for the thermo-voltage of exclusively cell-free bead samples in the test channel: a zero measurement.
20 Key to drawings
Stand der Technik
Prior art
Zu full rung
Supply
Messung
Measurement
Abfuhrung
Drainage
Messkurven
Test curves
A: Verlauf der Thermospannung bei zyklishcer Dosierung von Wasser
A: Characteristic of the thermovoltage with cyclical dosage of water
B: Temperaturanstieg an der Kupferhalterung
B: Temperature rise in the copper holder
C: Riickgang der Heizleistung bei Dosierung
C: Decline of the heating power during dosage
Messkurve
Test curves
A: Thermo spannung bei Messung von cfu in der Messkammer
A: Thermovoltage in a measurement of 5• 106 cfu in the test chamber
12
B: Thermo spannung bei Messung von cfu in der Messkammer
B: Thermovoltage in a measurement of 5• 105 cfu in the test chamber
C: Nullmessung - nur Beads in der Kammer
C: Zero measurement - only beads in the chamber
The device 10 for determining the effect of nanoparticle materials on living cells by measuring the thermal power produced by the cells by means of a chip calorimeter 40 illustrated in Figure 3 contains as the chip calorimeter at least the following: 5 - a through-flow test chamber 11 with a test channel 47 and a supply channel 12 for the supply of magnetic-bead samples 16 prepared with living cells producing thermal power and brought into contact with at least one nanoparticle material, and with a drainage channel 13 for the bead samples 16 and the transport fluid 17 used for a transport of the bead samples,
10 - a thermostat 15, to which the through-flow test chamber 11 is thermally coupled and which achieves a partial thermostatting of the transport fluid 17 used for the transport,
- a permanent magnet 18, which is positioned on the surface 19 of the through-flow test chamber 11 and which engages with its magnetic field strength in the through-flow chamber 11,
15 - a pivot device 20 holding the permanent magnet 18, wherein the pivoting of the permanent magnet 18 can take place away from the surface 19 up to a predetermined spacing distance from the surface 19, and
- four thermopiles 24, 25, 26, 27, which are in contact with the through-flow test chamber 11 arranged opposite to the permanent magnet 18,
20 wherein the following are further allocated to the device 10:
- a holding device 14 in which the through-flow test chamber 11 is vertically suspended at least by the supply channel 12 and/or the drainage channel 13,
- a pump unit 28, which is arranged downstream of the drainage channel 13 and used for a targeted drainage of the fluid 17, and
25 - a bead-sample trap 29, which is connected to the pump device 28 and in which the bead samples 16 are stored,
wherein the thermal-power measurement is implemented in the chip calorimeter 40 with a bead sample 16 magnetically fixed in the through-flow test chamber 11 after the settling of the thermal disturbances triggered by the transport of the bead samples, 30 wherein the thermal power produced by the cells is converted in at least one of the thermopiles 24, 25, 26, 27 into electrical signals, wherein the thermopiles 24, 25, 26,
13
27 are connected to the evaluation device 39 via signal lines 42, 43, 44, 45 and communicate the electrical signals to the evaluation device 39, and wherein the electrical signals are processed in the evaluation device 39 containing a computer 41 by means of computer-software technology and technical and biological 5 algorithms to form displays, which reproduce the response of the living cells to the contact with the material of the nanoparticles on the basis of the measured thermal power produced by the cells.
The displays can be output as information or data, for example, in tabular form and/or 10 in the form of a curve.
Accordingly, the chip calorimeter 40 in Figure 3 for measuring the thermal power of magnetic samples 16 comprises at least:
- a through-flow test chamber 11 with a test channel 47 and a supply channel 12 for 15 the supply of samples 16 and with a drainage channel 13 for the samples 16, in which a transport of the samples 16 by means of a transport fluid 17 takes place via a pump unit 28 connected to the drainage channel 13,
- at least one thermopile 24, 25, 26, 27 for registering the thermal power and conversion into electrical signals,
20 an evaluation unit 38 connected via signal lines 42, 43, 44, 45 to the thermopiles 24, 25, 26, 27, which evaluates the electrical signals by means of specified computer-software technology,
wherein, according to the invention,
the test channel 47 of the through-flow test chamber 11 is orientated vertically, and 25 the following are further provided:
a permanent magnet 18, which is positioned on the surface 19 of the through-flow test chamber 11 and which engages with its magnetic field strength in the through-flow test chamber 11 and is used for fixing the magnetic samples 16,
a pivot device 20 holding the permanent magnet 18, wherein the pivoting of the 30 permanent magnet 18 takes place away from the surface 19 up to a specified spacing distance from the surface 19 and back again in order to cancel the fixing of the magnetic samples 16,
wherein at least one thermopile 24, 25, 26, 27 is in contact with the through-flow test chamber 11 arranged opposite to the permanent magnet 18 in order to register the 35 thermal power of the magnetic sample 16.
14
As already indicated above, the magnetic samples 16 can be magnetic-bead samples.
A magnetic-bead sample 16 for implementing measurements before introduction into the supply channel 12 can comprise at least un-prepared magnetic beads, magnetic 5 beads prepared with living cells, magnetic beads prepared with living cells already contacted with nanoparticles or magnetic beads prepared with living cells still to be contacted with nanoparticles.
Accordingly, a bead sample can comprise magnetic beads with adsorbed living cells
10 applied to their surface, which have had optionally a contact treatment with nanoparticles for a defined time or no contact treatment with nanoparticles before flushing into the through-flow test chamber 11, wherein the influence of the material of the nanoparticles on the living cells can change their metabolic thermal power.
15 The magnetic beads used can be composed of several individual particles of paramagnetic iron oxide (y-Fe203; maghaemite) and provide a bead-like shape or droplet-like shape of an agglomeration, which is surrounded by a protective layer. The agglomeration can be enclosed with polyethylene imine as ligand, which represents a strong non-specific anionic exchanger. The magnetic beads used for the measurements
20 can be 0.5 |xm to 200 |xm in size.
The supply channel 12 and the drainage channel 13 in the chip calorimeter 40 of the device 10 represent cannulas and can be realised as steel capillaries.
25 The pivot device 20 can contain a plate spring 22 attached between the permanent magnet 18 and the holding device 21 and a filament 23 attached to the plate spring 22, wherein the filament 23 is used to deflect the plate spring 22 away from the surface 19 of the through-flow test chamber 11.
30 The pivot device 20 can also provide a spring 22 attached between the permanent magnet 18 and the holding device 21 and a displaceable sliding magnet (not illustrated) corresponding with the permanent magnet 18, which, by means of its mobility in the direction towards the permanent magnet 18, lifts the permanent magnet 18 from the surface 19 and guides it out of its active magnetic range with
15
regard to the through-flow test chamber 11 and, dependent upon the re-polarisation of the sliding magnet, back to the surface 19 again.
The bead-sample trap 29, which is connected to the pump unit 28, provides at least 5 one filter magnet 30, 31, 32, which filters the bead samples 16 from the flowing fluid 17 captures them and accumulates them on itself.
Between the pump unit 28 and the bead-sample trap 29, a T-piece 33 can be connected, at the branching 34 of which a syringe 35 is connected, with which a 10 cleaning fluid 36 can be introduced into the bead-sample trap 29 to clean any bead samples 16 or respectively nanoparticles still contaminated with cells or cell debris.
In the region of the holding device 14, a temperature sensor 37, of which the electrical signals are supplied to the evaluation device, can be brought into contact with the 15 supply channel 12.
A funnel 38 can be allocated to the supply channel 12 for filling transport fluid 17 with the prepared bead sample 16 disposed therein into the supply channel 12.
20 The measurement of the effect of the material of the nanoparticles consists substantially in at least one comparison measurement of magnetic-bead samples 16 prepared with living cells with regard to the thermal power of the living cells produced with reference to the presence or absence of a time-defined contact between the respective cell structure and the material of the nanoparticles under investigation. 25 Accordingly, the contact can have taken place either at a defined time before flushing into the through-flow test chamber 11 or can also take place continuously during the passage through the through-flow test chamber 11.
The contact treatment between the magnetic beads, the living cells adsorbed on them 30 and the nanoparticles can be implemented, for example, with different concentrations of the nanoparticles and also taking into consideration the concentration ratio between living cells and nanoparticles dependent upon the specified evaluation modality.
16
The method of functioning of the device 10 will be explained in greater detail with reference to Figure 3 and Figure 4a, Figure 4b and Figure 4c. Figure 4a shows an enlarged detail of the test region 46 with a test channel 47 during the supply of magnetic-bead sample 16 prepared with cells via the supply channel according to 5 Figure 3. Figure 4b shows an enlarged detail of the test region 46 with the test channel 47 at the moment of the thermal-power measurement of the magnetically arrested magnetic-bead sample 16 prepared with cells, and Figure 4c shows an enlarged detail of the test region 46 with the test channel 47 during the drainage/flushing out of the magnetically arrested magnetic-bead sample 16 prepared 10 with cells from the test channel 47 associated with the through-flow test chamber 11 of the chip calorimeter 40 and the pivoting away of the permanent magnet.
Accordingly, the following is implemented:
- A through-flow test chamber 11 is provided with a test channel 47 and at least one 15 vertically arranged channel 12 for supply and a channel 13 for drainage of at least one magnetic-bead sample 16 prepared with cells.
- The flow-test chamber 11 is suspended by the cannulas realising bead-sample transport channels 12, 13 within the holding device 14, which is thermally coupled to
20 the thermostat 15 of the chip calorimeter 40 and performs a partial thermostarting of the transport fluid 17 necessary for the transport of the bead samples.
- The permanent magnet 18 is pressed via a spring 22 against the surface 19 of the through-flow test chamber 11. In order to lift the permanent magnet 18, the spring 22
25 is deflected mechanically via a thin filament 23.
- To introduce a bead sample 16, the bead sample 16 is flushed with the assistance of a flow of fluid (for example, water or culture medium) 17 via the supply channel 12 into the through-flow test chamber 11 and held at the level of the permanent
30 magnet 18 attached to the surface 19, of which the magnetic field strength engages in the through-flow test chamber 11.
35
- The bead sample 16 is then disposed within the through-flow test chamber 11 in the region of at least one thermopile 24, 25, 26, 27 in contact with the surface 19.
17
- The thermal power measurement is implemented with regard to the bead sample 16 fixed at the positional level of the permanent magnet 18, after the settling of thermal disturbances triggered by the transport of the bead sample, in at least one of the thermopiles 24, 25, 26, 27 also attached to the surface of the through-flow test
5 chamber 11.
- After completion of the thermal-power measurement, the permanent magnet 18 is lifted from the surface 19, and the bead sample 16 is flushed out with the assistance of the flow of fluid 17 and captured outside the chip calorimeter 40 in the bead-sample
10 trap 29.
The following section presents a brief explanation of the signal generation in the case of dosages of cells to bead samples 16.
15 The signal behaviour or the thermal behaviour of the chip calorimeter 40 is investigated in the case of a dosage via the bead-sample transport channel 12-47-13. By determining the difference in thermovoltage AU between two adjacent thermopiles 25, 26, a corrected signal is generated during the signal evaluation. In this manner, interference effects such as a baseline drift or noise can be eliminated.
20 Accordingly, the test signal from thermopile 25 is subtracted from the test signal of thermopile 26. In this context, the bead sample 16 acting as the thermal-power source is positioned at thermopile 26 and adjacent to thermopile 25. Both thermopiles 26, 25 are therefore exposed to the same interference. In this manner, a high resolution of 20nW (0.1 |TV) can be achieved.
25
Figure 5a shows a typical characteristic of the thermovoltage, and Figure 5b shows a typical characteristic of the temperature measured by the temperature sensor 37 at the holding device 14, and Figure 5c shows a typical characteristic of the control power of the inner thermostat 15. The rise in temperature shows that the transport fluid 17
30 provides a relatively higher temperature than the set temperature of the thermostat 15. Accordingly, the temperature control reacts by lowering the control power. The strongly exothermic changes in the thermopile signals show that the heat introduced by the increased fluid temperature is not completely compensated before entry into the test channel 47 of the through-flow test chamber 11. However, it can be seen that the
35 settling of the temperature disturbance has already ended approximately 7 min after
18
the start of the dosage, and accordingly, the thermal power of the bead sample 16 can be measured with reference to the test channel 47 when free from bead samples. If a culture medium (LB-medium) is dosed instead of water, no changes other than the effects named previously occur.
5
Figure 6a shows a test curve for 5-106 cfu on bead samples 16. By comparison with this, a test curve is shown, in which, by contrast, only 5-105 cfu are contained in the through-flow test chamber 11 (Figure 6b). If bacteria are disposed in the test channel 47, a time-limited, constant signal (plateau) is obtained after the settling of 10 the dosage effect. The modulus of the thermovoltage difference AU with reference to the baseline increases with the number of bacteria in the test channel 47 (Figure 6a). Similarly, a new settling of the test signal can then be detected. The fewer bacteria there are in the test channel 47, the longer the plateau phase lasts (Figure 6b).
15 The differences in the characteristic of the test curves can be explained as follows: regardless of how many bacteria are disposed in the test channel 47, they can only produce a limited heat of 450 kJ per mole O2 under aerobic conditions. So long as oxygen and carbon substrate are present in excess, a saturation of the substrate is present. Accordingly, if the quantity of biomass is regarded as constant for a short 20 testing time, the rate of growth is maximal under given conditions and therefore constant. The quantity of bacteria is decisive only with regard to the thermal power, that is, how rapidly the oxygen is metabolised and accordingly how high the exothermic test signal is. The more bacteria are disposed in the test channel 47, the more rapidly the oxygen is consumed, and accordingly, the shorter the plateau is. In 25 Figure 6a only a short time of approximately 3 min elapsed until the metabolic activity, and therefore the thermal production of the bacteria, subsided. Beyond this, it is evident from Figure 6a that the test signal does not go back directly to the baseline, which suggests that the bacteria have adapted to aerobic living conditions.
30 Figure 6c shows the test curve characteristic with a zero measurement. In this case, only bead samples without bacteria are dosed. At the end of the dosage, the test signal immediately returns to the baseline.
19
With the device 10, including the evaluation device 39 which contains a computer 41, a method for testing the cytotoxic effect of nanoparticles materials on living cells (microorganisms and bacteria) and on eukaryotic cells/organisms is implemented on the basis of the thermal power produced respectively by the cells, with reference to 5 the thermal power measured by means of computer-software technology and technical and biological algorithms.
In this context, a demonstration of the cytotoxic effect of the nanoparticle materials is performed by means of the computer 41 through colorimetric detection of the thermal 10 power produced by the biological objects (metabolic thermal power) and the associated variation resulting from the effect of the nanoparticle materials. With regard to the cells/objects under investigation, the following applies:
The thermal power of the cells can be measured in cultures which are present in the form of a biofilm or are otherwise immobilised (for example, coupling via antibody-15 antigen interaction or electrostatically) on magnetic beads.
- The cultures can comprise one (clonal) or several (mixed culture) cell species.
- The cells under test can be of prokaryotic or eukaryotic origin.
20
- The cells under test can be naturally occurring cells or genetically modified cells.
- The cells under test can be artificially preserved cell cultures (for example HeLa cells).
25
The measurement of the metabolic thermal power is performed as already described by means of the chip calorimeter 40 according to the invention.
The advantages of the use of the chip calorimeter 40 with regard to the test organisms 30 are as follows:
- a sensitive detection of thermal power (less than lOOnW test resolution)
- low device costs
- rapidly implemented measurements
- the use of small quantities of test organisms, which is associated with a further 35 substantial cost savings in the case of eukaryotic cell cultures
20
- use for determining the effect on biofilms is possible
- the possibility of online measurement is provided, and accordingly, a rapid measurement of the effect of the test organisms.
21
List of reference numbers
1
Chip calorimeter according to the prior art
2
Chip carrier
5
3
Chip
4
Test chamber
5
Flow channel
6
Thermopile arrangement
7
Cover foil
10
8
Holding device
9
Fluid
10
Device according to the invention
11
Through-flow test chamber
12
Supply channel
15
13
Drainage channel
14
Holding device
15
Thermostat
16
Magnetic-bead sample
17
Transport fluid
20
18
Permanent magnet
19
Surface
20
Pivot device
21
Holding device
22
Spring
25
23
Filament
24
First thermopile
25
Second thermopile
26
Third thermopile
27
Fourth thermopile
30
28
Pump unit
29
Bead-sample trap
30
First filter magnet
31
Second filter magnet
32
Third filter magnet
35
33
T-piece
34
35
36
37
38
39
40
41
42
43
44
45
46
47
22
Branching Syringe Cleaning fluid Temperature sensor Funnel
Evaluation device
Chip calorimeter according to the invention Computer
First electrical signal line Second electrical signal line Third electrical signal line Fourth electrical signal line Test region Test channel
23
Claims (1)
1. A device for determining the effect of nanoparticle materials on living cells by measuring the thermal power produced by the cells by means of chip calorimeter, 5 comprising at least,
as the chip-calorimeter:
- a through-flow test chamber with a test channel and with a supply channel for the supply of magnetic-bead samples prepared with living cells producing thermal power and brought into contact with at least one nanoparticle material, and with a drainage
10 channel for the bead samples and a transport fluid provided for the transport of bead samples ,
- a permanent magnet, which is positioned on the surface of the through-flow test chamber and which engages with its magnetic field strength in the through-flow test chamber,
15 - a pivot device holding the permanent magnet, wherein the pivoting of the permanent magnet takes place away from the surface towards a predetermined spacing distance from the surface and back again, and
- at least one thermopile, which is in contact with the through-flow test chamber arranged opposite to the permanent magnet;
20 wherein, moreover, the following are allocated to the device:
- a holding device, on which the through-flow test chamber is vertically suspended at least by the supply channel and/or the drainage channel,
- a pump unit, which is arranged downstream of the drainage channel and used for a targeted drainage of the transport fluid,
25 and
- a bead-sample trap, which is connected to the pump unit and in which the bead samples are stored, wherein the thermal power measurement is implemented in the chip calorimeter on the bead sample magnetically fixed in the through-flow test chamber after the settling of the thermal disturbances triggered by the bead-sample
30 transport, wherein the thermal power produced by the cells is converted into electrical signals in at least one of the thermopiles, wherein the thermopiles are connected to an evaluation device via signal lines and communicate the electrical signals to the evaluation device, and wherein the electrical signals are processed to form displays in the evaluation device containing a computer by means of computer-software 35 technology and technical and biological algorithms which reproduce the response of
24
the living cells to the contact with the material of the nanoparticles on the basis of the measured thermal power produced by the cells.
2. The device according to claim 1,
5 characterised in that the chip calorimeter is integrated in a thermostat, to which the through-flow test chamber is thermally coupled and which achieves a partial thermostatting of the transport fluid used for the necessary transport.
10 3. The device according to claim 1,
characterised in that the supply channel and the drainage channel represent cannulas and are realised as steel capillaries.
15 4. The device according to claim 1,
characterised in that the pivot device contains a spring mounted between the permanent magnet and the holding device and a filament attached to the spring, wherein the filament is used to deflect the spring away from the surface of the through-flow test chamber.
20
5. The device according to claim 1,
characterised in that the pivot device provides a spring mounted between the permanent magnet and the holding device and a displaceable magnet corresponding with the permanent magnet, 25 which, by means of its mobility in the direction towards the permanent magnet lifts the permanent magnet from the surface and guides it out of its range of magnetic action with regard to the through-flow test chamber and, dependent upon the re-polarisation of the magnet, guides it back to the surface.
30 6. The device according to claim 1,
characterised in that the bead-sample trap, which is connected to the pump unit provides at least one filter magnet, which filters the bead samples from the flowing transport fluid accumulating them against itself.
35
25
7. The device according to claim 6,
characterised in that,
between the pump unit and the bead-sample trap, a T-piece is provided, at the branching of which a syringe is mounted, with which cleaning fluid can be guided into 5 the bead-sample trap to clean the bead samples still contaminated with cells or cell debris.
8. The device according to claim 1,
characterised in that
10 a temperature sensor is mounted in the region of the holding device in contact with the supply channel.
9. The device according to claim 1,
characterised in that
15 a funnel for filling transport fluid, with the prepared bead sample disposed in it, into the supply channel is allocated to the supply channel.
10. The device according to claim 9,
characterised in that
20 the transport fluid provided for flushing in and flushing out the bead samples is water or a liquid culture medium.
11. The device according to claim 1,
characterised in that
25 a magnetic-bead sample for the implementation of measurements before introduction into the supply channel comprises at least one un-prepared magnetic bead, a magnetic bead prepared with living cells, a magnetic bead prepared with living cells already contacted with nanoparticles or a magnetic bead prepared with living cells still contacting nanoparticles.
30
12. The device according to claim 11,
characterised in that the magnetic-bead samples comprise at least one un-prepared magnetic bead or a magnetic bead prepared with living cells substantially for comparative measurements 35 with the magnetic-bead samples made from a magnetic bead prepared with living cells
26
already contacted with nanoparticles and/or a magnetic bead prepared with living cells continuously contacted with nanoparticles.
13. The device according to claim 11 or 12,
5 characterised in that a magnetic-bead sample accordingly comprises a magnetic bead with adsorbed, living cells applied to its surface, which, before flushing into the through-flow test chamber optionally had a contact treatment with nanoparticles for a defined time or had no contact treatment with nanoparticles, wherein the influence of the material of the 10 nanoparticles on the living cells changes their metabolic thermal power.
14. The device according to claims 11 to 13,
characterised in that the magnetic beads used are composed of several individual particles of para-magnetic 15 iron oxide (y-Fe203; maghaemite) and provide a bead-like shape or droplet-like shape of an agglomeration which is surrounded by a protective layer of starch, wherein the agglomeration is coated with polyethylene imine as ligand, which represents a strong, non-specific anionic exchanger.
20 15. A chip calorimeter for measuring the thermal power of magnetic samples, comprising at least:
- a through-flow test chamber with a test channel and with a supply channel for the supply of samples and with a drainage channel for the samples, in which a transport of the samples is implemented by means of a transport fluid via a pump unit connected to
25 the drainage channel,
- at least one thermopile for registering the thermal power and conversion into electrical signals,
- an evaluation unit disposed in connection via signal lines with the thermopiles, which evaluates the electrical signals using specified computer-software means,
30 characterised in that the test channel of the through-flow test chamber is orientated vertically, and furthermore, the following are provided:
- a permanent magnet, which is positioned on the surface of the through-flow test chamber and engages with its magnetic field strength in the through-flow test chamber
35 and is used for fixing the magnetic samples,
27
- a pivot device holding the permanent magnet, wherein the pivoting of the permanent magnet takes place away from the surface up to a specified spacing distance from the surface and back again in order to cancel the fixing of the magnetic samples, and wherein at least one thermopile is disposed in contact with the through-flow test 5 chamber, arranged opposite to the permanent magnet in order to register the thermal power of the magnetic sample.
16. A method for determining the effect of nanoparticle materials on living cells by measuring the thermal power produced by the cells with the use of a device
10 according to claims 1 to 14 including a chip calorimeter according to claim 15, characterised in that comparison measurements are implemented between magnetic-bead samples prepared with living cells with regard to the thermal power of the living cells produced relative to the presence or non-presence of a contact for a defined time between the respective 15 cell structure and the respective material of the specified nanoparticle under investigation, wherein the contact took place either at a defined time before introducing the prepared magnetic-bead samples into the through-flow test chamber or takes place continuously during the passage through the through-flow test chamber, wherein the comparison measurements are evaluated by an evaluation device.
20
17. The method according to claim 16,
characterised in that a contact treatment between the magnetic beads and the living cells adsorbed on them and the nanoparticles, both with different concentrations of the adsorbed cells and the 25 nanoparticles, and also taking into consideration the concentration ratio between living cells and nanoparticles, is implemented dependent upon the specified evaluation modality.
18. The method according to claim 16 or 17,
30 characterised in that,
by means of a computer allocated to the evaluation device, a display of the cytotoxic effect of the nanoparticle materials is provided through the calorimetric detection of the production of heat by the biological objects in the form of a metabolic thermal power and its variation resulting from the effect of the nanoparticle materials,
28
wherein, with regard to the cells/objects under investigation, it is provided that the thermal power of the cells is measured in cultures, wherein:
- the cultures are present in the form of a biofilm or are immobilised through coupling via antibody-antigen interaction or electrostatically on magnetic beads or
5 - the cultures comprise one (clonal) cell type or several (mixed culture) cell types or
- the cells under test are of prokaryotic or eukaryotic origin or
- the cells under test are naturally occurring cells or genetically modified cells or
- the cells under test are artificially sustained cell cultures (e.g. He-La cells).
10 19. The method according to claims 16 to 18,
characterised in that,
when testing of the effect of the material of nanoparticles on microorganisms, the microorganisms are used in the form of biofilms, which are cultivated on magnetic beads as bead samples, wherein:
15 - the microorganisms cultivated by biofilm formation on the bead samples represent realistic models for the assessment of the cytotoxic effect of nanoparticle materials in the environment because of the high degree of heterogeneity and
- a cultivation of the biofilms on the magnetic-bead samples allows an automated bead-sample transfer through the chip calorimeter.
20
20. The method according to claims 16 to 19,
characterised in that the thermal-power measurement in the chip calorimeter of the device is implemented on at least one bead sample magnetically fixed in the through-flow test chamber, after 25 the settling of the thermal disturbances triggered by the transport of the bead-sample in the thermopiles, within at least one of the thermopiles also provided on the surface of the through-flow test chamber, connected via signal lines to the evaluation device containing a computer, and communicating electrical signals equivalent to the thermal power produced by the living cells.
30
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE201210003863 DE102012003863B3 (en) | 2012-02-22 | 2012-02-22 | Device, useful for determining effect of nanoparticle materials on living cells by measuring thermal power production of cells using chip-calorimeter, comprises flow measurement chamber, permanent magnet, pivot device, and thermopile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201303107D0 GB201303107D0 (en) | 2013-04-10 |
| GB2499727A true GB2499727A (en) | 2013-08-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB201303107A Withdrawn GB2499727A (en) | 2012-02-22 | 2013-02-21 | Chip calorimeter for determining the effect of nanoparticle materials on living cells |
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| Country | Link |
|---|---|
| DE (1) | DE102012003863B3 (en) |
| GB (1) | GB2499727A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112903755B (en) * | 2021-02-24 | 2023-06-02 | 太原理工大学 | Carbon dioxide sensor and preparation method thereof |
| CN113465789B (en) * | 2021-07-01 | 2022-05-24 | 东北大学秦皇岛分校 | Open micro-nano calorimeter system for cell metabolism heat detection |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998037408A1 (en) * | 1997-02-21 | 1998-08-27 | Institut für Physikalische Hochtechnologie e.V. | Micro-flow module for chemical analysis |
| US6079873A (en) * | 1997-10-20 | 2000-06-27 | The United States Of America As Represented By The Secretary Of Commerce | Micron-scale differential scanning calorimeter on a chip |
| US20080166727A1 (en) * | 2006-12-20 | 2008-07-10 | The Board Of Trustees Of The Leland Stanford Junior University | Heat and pH Measurement for Sequencing of DNA |
| WO2012097221A1 (en) * | 2011-01-14 | 2012-07-19 | The Charles Stark Draper Laboratory, Inc. | System and method for a microfluidic calorimeter |
| US20130029851A1 (en) * | 2011-05-27 | 2013-01-31 | Hesaam Esfandyarpour | Calorimeter sensor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19910392B4 (en) * | 1999-03-05 | 2005-03-17 | Clondiag Chip Technologies Gmbh | Micro column reactor |
-
2012
- 2012-02-22 DE DE201210003863 patent/DE102012003863B3/en not_active Expired - Fee Related
-
2013
- 2013-02-21 GB GB201303107A patent/GB2499727A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998037408A1 (en) * | 1997-02-21 | 1998-08-27 | Institut für Physikalische Hochtechnologie e.V. | Micro-flow module for chemical analysis |
| US6079873A (en) * | 1997-10-20 | 2000-06-27 | The United States Of America As Represented By The Secretary Of Commerce | Micron-scale differential scanning calorimeter on a chip |
| US20080166727A1 (en) * | 2006-12-20 | 2008-07-10 | The Board Of Trustees Of The Leland Stanford Junior University | Heat and pH Measurement for Sequencing of DNA |
| WO2012097221A1 (en) * | 2011-01-14 | 2012-07-19 | The Charles Stark Draper Laboratory, Inc. | System and method for a microfluidic calorimeter |
| US20130029851A1 (en) * | 2011-05-27 | 2013-01-31 | Hesaam Esfandyarpour | Calorimeter sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201303107D0 (en) | 2013-04-10 |
| DE102012003863B3 (en) | 2013-03-07 |
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