Classifications

• • 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
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
  • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
  • G01N33/54366—Apparatus specially adapted for solid-phase testing
  • G01N33/54373—Apparatus specially adapted for solid-phase testing involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
  • G01N33/5438—Electrodes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00277—Apparatus
  • B01J2219/00497—Features relating to the solid phase supports
  • B01J2219/00511—Walls of reactor vessels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00603—Making arrays on substantially continuous surfaces
  • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00603—Making arrays on substantially continuous surfaces
  • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
  • B01J2219/00612—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports the surface being inorganic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00603—Making arrays on substantially continuous surfaces
  • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
  • B01J2219/00623—Immobilisation or binding
  • B01J2219/00626—Covalent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00603—Making arrays on substantially continuous surfaces
  • B01J2219/00605—Making arrays on substantially continuous surfaces the compounds being directly bound or immobilised to solid supports
  • B01J2219/00623—Immobilisation or binding
  • B01J2219/0063—Other, e.g. van der Waals forces, hydrogen bonding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00583—Features relative to the processes being carried out
  • B01J2219/00603—Making arrays on substantially continuous surfaces
  • B01J2219/00653—Making arrays on substantially continuous surfaces the compounds being bound to electrodes embedded in or on the solid supports
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00709—Type of synthesis
  • B01J2219/00713—Electrochemical synthesis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00274—Sequential or parallel reactions; Apparatus and devices for combinatorial chemistry or for making arrays; Chemical library technology
  • B01J2219/00718—Type of compounds synthesised
  • B01J2219/0072—Organic compounds
  • B01J2219/00722—Nucleotides
• • C—CHEMISTRY; METALLURGY
  • C40—COMBINATORIAL TECHNOLOGY
  • C40B—COMBINATORIAL CHEMISTRY; LIBRARIES, e.g. CHEMICAL LIBRARIES
  • C40B40/00—Libraries per se, e.g. arrays, mixtures
  • C40B40/04—Libraries containing only organic compounds
  • C40B40/06—Libraries containing nucleotides or polynucleotides, or derivatives thereof
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S435/00—Chemistry: molecular biology and microbiology
  • Y10S435/817—Enzyme or microbe electrode

Definitions

• the present invention relates to microsystems for biological analyzes, usable in particular in the health sector, the food industry and the environment.
• microtechnologies in the biological field, thus making it possible, through integration and parallelization, to achieve high performance, speeds and sensitivities.
• microtechnologies lead to new solutions, both technical (miniaturization, integration) and economic (mass production), likely to boost the development of biosensors.
• EP-A-244 326 also describe a method for detecting and / or identifying a biological substance in a liquid sample using electrical measurements.
• the sample is brought into contact with a reagent-carrying plate comprising a ligand specific for the biological substance to be detected, this plate possibly being made of a semiconductor material such as silicon, and being coated with a silica insulating layer, then we measure the C and / or R components of the electrical impedance of the system to detect the presence of the biological substance in the sample.
• the present invention specifically relates to a biological analysis microsystem, based on the same principle, that is to say on the recognition reaction of the biological substance or analyte to be detected with a specific ligand, which makes it possible to on the one hand, to detect this recognition reaction by several types of combined measurements such as impedance and rheological measurements of viscosity and surface forces, and on the other hand, to carry out these measurements in the vicinity or within the active layer analyte-ligand.
• the device for detecting or assaying an analyte comprises: - a cell comprising at least one fixed electrode and at least one mobile electrode opposite the fixed electrode, the mobile electrode being able to be moved so as to approach and / or move away from the fixed electrode, the space between the electrodes forming a sample receiving cavity and the wall of at least one of the electrodes facing the receiving cavity being capable of fixing a specific ligand for the analyte to be detected, means for moving the mobile electrode, means for separately connecting the electrodes to an external electrical circuit, and means for measuring the impedance or the electric capacitance between the electrodes .
• the mobile electrode and the fixed electrode are both capable of fixing a specific ligand of the analyte to be detected, the ligands of the two electrodes being able to be identical or different.
• the electrodes and preferably both are covered with ligand.
• the means for moving the mobile electrode can be constituted by means for polarizing the fixed electrode and the mobile electrode.
• Fc . ⁇ SV 2 / e 2 , where ⁇ is the dielectric constant of the medium between the electrodes, V is the applied voltage, e is the average distance between the electrodes and S is the surface of the electrodes.
• This capacitive force thus makes it possible to ensure the displacement of the mobile electrode, provided of course that it is free to move in the device.
• the means for moving the mobile electrode are magnetic means.
• the means for moving the mobile electrode can also be constituted by excitation means using an inductive effect.
• the mobile electrode can be associated with turns supplied with electric current and subjected to the action of a magnetic field so as to generate a force in the desired direction of movement of the mobile electrode.
• the cell comprises a tank on a wall of which the fixed electrode is arranged, the mobile electrode is arranged opposite the fixed electrode on a mobile element mounted on the ( the) wall (s) of the tank by means of at least one flexible beam, so that the mobile electrode can approach or move away from the fixed electrode by deformation of the flexible beam, and of the contacts electric are arranged on the wall (s) of the tank, on said flexible beam and on the movable element to connect separately the fixed electrode and the mobile electrode to an external electrical circuit allowing to polarize the electrodes and to measure the capacitance between the fixed electrode and the mobile electrode.
• the means for moving the mobile electrode can be constituted by means for polarizing the fixed electrode and the mobile electrode.
• a second pair of electrodes formed respectively on a wall of the tank and on the mobile element so as to be opposite one of the another, and means of polarization of the pair of electrodes so as to 'cause movement of the movable member supporting the movable electrode.
• magnetic means for moving the mobile electrode can comprise a permanent magnet placed on the mobile element of the mobile electrode, and means for applying a magnetic field to this magnet.
• the device is advantageously produced from a silicon substrate with a buried silica layer.
• the bottom and the wall (s) of the tank are formed of silicon, the wall (s) are separated from the bottom by a layer of insulating silica, the mobile element and the flexible beams. are also formed of silicon, and the electrodes are formed of silicon made conductive by implantation of ions.
• the device of the invention can be used for the detection or the assay of analytes of various types. By way of example of such analytes, in particular in the medical field, mention may be made of antigens, haptens, antibodies, peptides, nucleic acid fragments (DNA or RNA), enzymes and enzyme substrates .
• At least one of the electrodes of the device is covered with a ligand specific for the analyte to be detected, for example by direct or indirect grafting of this ligand on the electrode (s).
• a ligand specific for the analyte to be detected for example by direct or indirect grafting of this ligand on the electrode (s).
• the specific ligands covering the electrode (s) are those which have at least one site for recognition of the analyte and which are capable of binding to the latter.
• the ligand-analyte pair can thus belong to the antigen-antibody, hapten-antibody, hormone receptor, DNA- C DNA, RNA-RNA C , enzyme-substrate, or any other association of biological molecules or not, capable of forming between they are complex.
• the use of a detection device comprising a mobile electrode has many advantages.
• the operation of grafting the ligand onto the electrode (s) can be carried out while avoiding the formation agglomerates, which makes it possible to obtain a homogeneous layer of ligand, as dense as possible.
• the fluidics are facilitated by allowing the fluid to be agitated at the electrodes, which leads to an increased probability of recognition between the analyte and the attached ligand, prevents the formation of agglomerates and makes it possible to obtain a homogeneous and dense active layer on the electrode (s).
• the fact of having a mobile electrode also makes it possible to detect the presence of analyte by using other measurements, for example a measurement of the viscosity of the sensitive layer by studying the damping of the movement. of the mobile electrode in this layer, after a series of alternating movements of this electrode.
• the presence of analyte can also be detected by measuring the surface mechanical forces at vicinity of the sensitive layer, as will be seen below.
• the invention also relates to a method for detecting or assaying an analyte in a liquid sample which comprises the following steps: a) introducing said sample into a cell comprising at least one fixed electrode and at least one mobile electrode located opposite the fixed electrode, said movable electrode being movable so as to approach or move away from the fixed electrode, at least one of said electrodes being coated with a specific ligand for the analyte to be detected and the sample being introduced between the electrodes with the movable electrode in a position remote from the fixed electrode; b) move the movable electrode at least once to bring it closer to the fixed electrode or to make it oscillate between a close position and a position distant from the fixed electrode; and c) measuring, during this displacement or after this (s) displacement (s), a parameter representative of the formation or not, between the electrodes, of a sensitive layer obtained by reaction of the ligand with the analyte to be detected.
• step b) the mobile electrode is moved at once or in several times to bring it closer to the fixed electrode, and then after each movement is measured in the step c), the electrical impedance between the electrodes, the measured value being compared with a reference value determined in the absence of analyte.
• step c) it is also possible to carry out several impedance measurements at different distances between the electrodes in order to have a record of the phenomena of variation of impedance due to the presence of the layer active formed by the ligand-analyte complex. It is thus possible to obtain separately the impedance of the intermediate layer and the impedance of the active layer.
• the mobile electrode is moved several times to make it oscillate between a close position and a distant position, then after these displacements, the capacitance between the electrodes as a function of time is measured in step c).
• step b the mobile electrode is moved only once to bring it closer to the fixed electrode, and measure in step c) during this displacement the capacity between the electrodes and the force applied to bring the mobile electrode closer.
• step c the capacity between the electrodes and the force applied to bring the mobile electrode closer.
• This measurement mode is more particularly intended for the determination of analytes having two recognition sites for the same specific ligand or for two different ligands or the mobile electrode and the fixed electrode of a mixture of two ligands.
• the mobile electrode and the fixed electrode are covered with different ligands or the mobile electrode and the fixed electrode with a mixture of two ligands.
• FIG. 1 is a perspective view of a detection device according to the invention.
• FIG. 2 is a view in vertical section of the device of the invention along the line XX 'of FIG. 1.
• FIGS 3 to 5 illustrate the main stages of preparation of the device of Figure 1.
• FIG. 6 schematically illustrates the device of FIG. 1 during the step of coating the electrodes and bringing it into contact with the sample, the electrodes being in a distant position.
• FIG. 8 is a diagram illustrating the viscosity of the liquid between the electrodes as a function of the distance between the electrodes, in the absence of analyte (curve 1) and in the presence of analyte (curve 1)
• Figure 9 illustrates the device of Figure
• FIG. 10 is a diagram illustrating the contact force between the electrodes as a function of the interelectrode distance, in the absence of analyte (curve
• Figure 1 there is shown in perspective a microsystem for biological analysis according to one invention.
• This microsystem comprises a measuring cell 1 of parallelepiped shape comprising on one of its side walls 2 a fixed electrode 3.
• a mobile electrode 5 is located opposite the fixed electrode 3 on a mobile element 7 mounted on the side walls opposite 9 and 11 of the cell, by means of flexible thin beams 13 and 15 which form a flexible mechanical connection between the movable element 7 and the walls 9 and 11.
• the fixed electrode 3 and the mobile electrode 5 are electrically isolated from each other by a layer electrical insulation 17 disposed on the side walls 2, 9, 11 and 22 of the cell above the bottom 19 thereof.
• the interior of the cell constitutes a cavity for receiving the liquid sample to be analyzed.
• Electrical contacts 21 and 23 respectively connect the fixed electrode 3 and the movable electrode 5 to an external circuit.
• This external circuit makes it possible in particular to apply appropriate voltages to the fixed electrode and to the mobile electrode, to control the movement of the mobile element 7 and of the associated electrode 5, to control the distance between the electrodes and carry out various measurements such as a measurement of the capacitance between the electrodes, possibly as a function of time and during the displacement of the mobile electrode.
• a permanent magnet 8 shown in phantom in the figures 1 and 2 and a field is created around the device
• the miscrosystem of the invention can be produced by micro-machining methods such as those used in microelectronics.
• micro-machining methods such as those used in microelectronics.
• devices of very small dimensions for example 3 mm ⁇ 3 mm on a side with an interelectrode space which can range from 0.1 ⁇ m in the close position to 10 ⁇ m in the remote position.
• FIGs 3 to 5 there is shown schematically, the realization of a microsystem of this type starting from a SOI type substrate (Silicon on Insulator "(silicon on insulator).
• the first step of forming the electrodes 3 and 5 is shown in the SOI substrate which comprises an intermediate layer of silica 17 with a thickness of approximately 4000 ⁇ , between its lower part 19. made of silicon and its upper part 20 also made of silicon, about 5 ⁇ m thick.
• the silicon is modified locally in the upper part 20 by implantation of ions, for example of boron, through a mask defining the zones to be implanted which correspond to the electrodes. Sufficient energy is used for the implantation to make the silicon conductive on these areas up to the intermediate layer of silica 17.
• External electrical contacts 21 and 23 are produced by conventional techniques, such as those usually used in microelectronics, for example by metallic deposit or followed by etching.
• the side walls 2, 9 are then produced,
• holes 8 are also made in the element 7, also by photolithography, which will be useful later to release the movable element 7 from the bottom 19.
• FIG ' 5 there is shown the process step in which the movable element is released 7. This can be done by dissolving the layer of Si0 2 covering the bottom 19, by means of hydrofluoric acid introduced by the openings previously made between the movable element 7 and the side walls 2 and 22, as well as through the holes 8. This gives an elimination of the layer 17 except on the walls 2, 22, 9 and 11 of the device.
• 2 can be used for analyzes, in particular biological analyzes, after fixation on one or both electrodes of a specific ligand L of the analyte A to be detected.
• the ligand L can be fixed by conventional techniques, for example by adsorption on the electrode after having oxidized it very superficially, or by forming a covalent bond between the electrode and the ligand using a bifunctional coupling reagent capable of reacting both with the electrode and with the ligand.
• a bifunctional coupling reagent capable of reacting both with the electrode and with the ligand. The use of such reagents is well known.
• silane derivatives comprising an alkoxysilane group and an NH 2 group separated from one 'other by a hydrocarbon chain. Techniques of this type are described in references 1, 3 and 4 cited above.
• This attachment may also be effected by the techniques described in r OA-94/22889 (reference 6).
• This fixing is preferably carried out before use, with the electrodes 3 and 5 in the remote position.
• the electrodes 3 and 5 are shown diagrammatically as well as part of the bottom 19 and of the movable element 7 of the device of FIG. 1.
• the electrodes are in the distant position at a distance distant from e , for example 2 ⁇ m, and they are covered with specific ligand L.
• the reagents and the ligand are introduced into the tank of the device; thereby also securing a ligand on the bottom 19 and on the movable member 7, as can be seen in this figure.
• the sample to be analyzed is introduced into the device, the electrodes always being in the remote position.
• the sample contains the analyte A, which forms with the ligand L an LA complex or active layer with a thickness less than 1000 ⁇ on the walls of the electrodes and of the device, as shown in FIG. 6.
• the presence or absence of this complex is then checked, for example by bringing the mobile electrode 5 closer to the fixed electrode 3 so as to have a close distance d r between the electrodes, which is for example 2000 ⁇ , ie 0.2 ⁇ m , and then performing or during this reconciliation the measurement of a significant parameter.
• FIG. 7 shows the device in this position where the inter-electrode distance d r corresponds to a close position. It is thus noted that the active layer (LA complex) occupies practically the entire space between the electrodes 3 and 5.
• the presence of this layer is detected by measuring the impedance between the electrodes 3 and
• an appropriate voltage is applied to the electrodes 3 and 5 and the intensity of the current flowing in the cell is measured.
• the presence of the analyte in the sample is detected by determining the viscosity of the sensitive layer between the electrodes.
• This damping depends on friction and therefore on the viscosity of the layer of molecules between the electrodes, in particular its thickness.
• FIG. 8 shows the evolution of the viscosity ⁇ of the liquid as a function of the distance d between the electrodes.
• Curve 1 of this figure represents this evolution in the absence of analyte.
• Curve 2 represents this evolution in the presence of analyte.
• the viscosity does not vary significantly when the interelectrode distance remains greater than the thickness of the layers of the ligand alone or of the layers of the ligand-analyte complex.
• This increase in viscosity can be detected after having made the mobile electrode oscillate between a close position and a distant position, by measuring the capacitive variation between the electrodes during the damping of the movement of the mobile electrode.
• the close position must correspond to an interelectrode distance less than d_.
• the presence of the analyte is detected by measuring the contact forces between the electrodes.
• This third embodiment is more particularly used when the analyte has two recognition sites for a specific ligand or for two different specific ligands.
• FIG. 9 This case is illustrated in FIG. 9 where we see the fixed 3 and mobile 5 electrodes in the close position covered respectively with ligands L and
• L '(L' L or L ' ⁇ L), and I' analyte A or A 'which has two identical (A) or different (A') recognition sites.
• the analyte A or A ' is bound both to the ligand of electrode 3 and to the ligand of electrode 5, which corresponds to a bonding phenomenon between the electrodes.
• FIG. 10 shows the evolution of the contact force f between the electrodes as a function of the interelectrode distance d.
• Curve 3 illustrates this development in the absence of analyte and curve 4 illustrates this development in the presence of analyte. So, we notice that the contact force increases rapidly when the interelectrode distance reaches the thickness of the sensitive layer, either di without analyte, or d2> d j with analyte. This therefore also makes it possible to determine the presence of analyte.
• This contact force can be determined by measuring the capacity between the electrodes and the voltage required to bring the movable electrode closer.
• the value of the capacity makes it possible to determine the inter-electrode distance and the force applied depends on the thickness of the sensitive layer.
• a device of this type was used to detect the presence of known DNA sequences in an aqueous solute by using the complementary DNA sequence as ligand, and by carrying out the binding of the ligand by grafting onto a polymer itself. - same electrodeposited on the fixed and mobile electrodes.

Landscapes

• Health & Medical Sciences (AREA)
• Immunology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Biomedical Technology (AREA)
• Chemical & Material Sciences (AREA)
• Hematology (AREA)
• Urology & Nephrology (AREA)
• Biotechnology (AREA)
• Biochemistry (AREA)
• Cell Biology (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Microbiology (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Pathology (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
• Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9499288

Family Applications (1)

Country Status (5)

Families Citing this family (23)

Family Cites Families (11)

• 1996
  • 1996-12-30 FR FR9616200A patent/FR2757948B1/fr not_active Expired - Fee Related
• 1997
  • 1997-12-29 WO PCT/FR1997/002439 patent/WO1998029739A1/fr not_active Ceased
  • 1997-12-29 JP JP52970598A patent/JP2001507454A/ja active Pending
  • 1997-12-29 US US09/331,578 patent/US6133046A/en not_active Expired - Fee Related
  • 1997-12-29 EP EP97953962A patent/EP0950185A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events