Abstract: A device, method and kit for the electrophoretic separation and purification of charged and neutral compounds in an analyte solution. The device comprises a chamber (1), at least one wall of which is composed of a chemical buffering system (4). A potential difference is applied across the buffering system, resulting in the charged and neutral compounds being differentially separated by extraction of the charged compounds into the buffering system. The device also comprises means for collecting the separated compounds, preferably in ampholyte-free or buffer-free solution and optionally means for recycling the separated fractions.

Abstract: A method to optimize the amperometric detection in a microsystem consists in limiting the detection to times when the diffusion layer (18-20) of the analyte to detect remains smaller than the microchannel (7) height. The charge detected during the second part of the amperometric measurement (which corresponds to the integral of the measured current over the corresponding time period) can also be considered so as to remove the contribution of the capacitive current and, when applicable, of the current resulting from the reduction or oxidation of the analyte molecules present in a recess above the electrode at the beginning of the detection. A microfluidic amperometric sensor for performing the method comprises at least one microchannel (7) having at least one electrode (15-17), integrated in one wall of the microchannel, and having a characteristic length or radius which is smaller than half the microchannel height.

Abstract: The present invention relates to an apparatus and method for the separation and purification of charged and neutral compounds in an analyte solution by electrophoretic means using a plurality of compartments (1) to contain the analyte solution, an chemical buffering system (2) to fix a pH value or a pH gradient in its portion(s) contacting the analyte solution and an electrical field imposed by electrical means (4) disposed in at least two of said compartments. This invention allows one to differentially separate charged and neutral compounds, to extract the migrating compounds from the chemical buffering system (2), to recover the purified compounds mainly in solution and to collect them in the various compartments (4), preferably at various pI.

Abstract: The present invention relates to an apparatus to dispense a sample for subsequent electrospray ionisation (ESI) mass spectrometry (MS) analysis, to a method of fabricating such apparatus and to applications of such apparatus in biological and chemical analysis. The apparatus consists of an electrically non-conductive substrate comprising at least two covered microstructures (generally microchannels) having one extremity formed at the edge of the substrate, one of said microstructures containing the sample to be dispensed into a mass spectrometer by electrospray ionisation and at least a second of said microstructure containing a fluid used as sheath liquid or sheath gas, said at least two microstructures being formed in such a manner that the sample and the sheath liquid/gas come in contact to each other and/or are mixed directly in the Taylor cone of the spray.

Abstract: The present invention relates to an apparatus and a method of fabricating the apparatus for dispensing a sample for subsequent analysis by mass spectrometry. The apparatus comprises a polymer substrate (1), in which a covered microchannel (3) has been etched, a wall of the microchannel comprising an electrically conductive material (2) for applying a voltage allowing the sample to be sprayed into a mass spectrometer from the open end (4) of the microchannel. The present application also discloses various applications of the apparatus.

Abstract: The present invention relates to an apparatus and method for the separation and purification of charged and neutral compounds in an analyte solution by electrophoretic means using a plurality of compartments (1) to contain the analyte solution, an chemical buffering system (2) to fix a pH value or a pH gradient in its portion(s) contacting the analyte solution and an electrical field imposed by electrical means (4) disposed in at least two of said compartments. This invention allows one to differentially separate charged and neutral compounds, to extract the migrating compounds from the chemical buffering system (2), to recover the purified compounds mainly in solution and to collect them in the various compartments (4), preferably at various pI.

Abstract: Apparatus method for performing an electrochemical assay or a reaction, using electrical conductivity and/or power in order either to perform a reduction or an oxidation or an ion transfer reaction, or to perform conductimetry and/or impedance measurements, or to generate an electric field in a solution, or to perform any combination of the aforesaid. The apparatus comprises at least one micro-chip (1) possessing a microstructure (2) (for example a microchannel or array or network of microchannels) having a tip end (3) adapted for uptake of a fluid sample into and/or discharge of a fluid sample from said microstructure, a microfluidic connection end (4) and an integral electrode.

Abstract: A low temperature method of bonding two polymer sheets (2, 3) without adhesive, at least one of said polymer sheets comprising a microstructure (1) or a network of microstructures, comprises the steps of treating at least a portion of one surface of one of said polymer sheets by using a cold plasma or a laser beam so as to physically activate said portion at low temperature, placing the two polymer sheets in contact, with the activated portion of said one sheet in contact with the other sheet, and subjecting said sheets to pressure and to a temperature below the melting and/or glass transition temperature of either of said polymer sheets, thereby bonding said sheets and forming a sealed micro-structure and/or network of micro-structures. The method is used to fabricate a micro-analytical device for use in biological and/or chemical applications.

Abstract: The present invention relates to an apparatus and a method of fabricating the apparatus for dispensing a sample for subsequent analysis by mass spectrometry. The apparatus comprises a polymer substrate (1), in which a covered microchannel (3) has been etched, a wall of the microchannel comprising an electrically conductive material (2) for applying a voltage allowing the sample to be sprayed into a mass spectrometer from the open end (4) of the microchannel. The present application also discloses various applications of the apparatus.

Abstract: A device, method and kit for the electrophoretic separation and purification of charged and neutral compounds in an analyte solution. The device comprises a chamber (1), at least one wall of which is composed of a chemical buffering system (4). A potential difference is applied across the buffering system, resulting in the charged and neutral compounds being differentially separated by extraction of the charged compounds into. the buffering system. The device also comprises means for collecting the separated compounds, preferably in ampholyte-free or buffer-free solution and optionally means for recycling the separated fractions.