Zeptosens Ag

Ciba-geigy Corporation

Other

Hitachi, Ltd.

Andreas Manz

Carlo S Effenhauser

D Jed Harrison

Keiji Tsukada

Yoshio Watanabe

Yuji Miyahara

Junkichi Miura

Hiroyuki Miyagi

Elisabeth Verpoorte

A microfluidic device for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electrolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. Means are provided for electrokinetically injecting the sample into the sample volume.

Microfluidic device for controlling sample introduction in microcolumn separation techniques and sampling device

In a method for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electrolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. The supply and drain channels each are inclined to the electrolyte channel. Means are provided for electrokinetically injecting the sample into the sample volume. The resistance to flow of the source and drain channels with respect to the electrolyte buffer is at least about 5% lower than the respective resistance to flow of the electrolyte channel.

Method for controlling sample introduction in microcolumn separation techniques and sampling device

In a method for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CRE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electrolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. The supply and drain channels each are inclined to the electrolyte channel. Means are provided for electrokinetically injecting the sample into the sample volume. The resistance to flow of the source and drain channels with respect to the electrolyte buffer is at least about 5% lower than the respective resistance to flow of the electrolyte channel.

In a method for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electrolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. The supply and drain channels each are inclined to the electrolyte channel. Means are provided for electrokinetically injecting the sample into the sample volume. The resistance to flow of the supply and drain channels with respect to the electrolyte buffer is at least about 5% lower than the respective resistance to flow of the electrolyte channel.

In a method for controlling sample introduction in microcolumn separation techniques, more particularly in capillary electrophoresis (CE), where a sample is injected as a sample plug into a sampling device which comprises at least a channel for the electrolyte buffer and a supply and drain channel for the sample. The supply and drain channels discharge into the electolyte channel at respective supply and drain ports. The distance between the supply port and the drain port geometrically defines a sample volume. The injection of the sample plug into the electrolyte channel is accomplished electrokinetically by applying an electric field across the supply and drain channels for a time at least long enough that the sample component having the lowest electrophoretic mobility is contained within the geometrically defined volume. The supply and drain channels each are inclined to the electrolyte channel. Means are provided for electrokinetically injecting the sample into the sample volume. The resistance to flow of the source and drain channels with respect to the electrolyte buffer is at least about 5% lower than the respective resistance to flow of the electrolyte channel.

A miniaturized detector cell (4) having a measuring chamber volume of 25 fl-1 .mu.l is described. In spite of its miniaturized construction, the detector cell has an optical path length of about 0.1-100 mm. The incident measuring light (R) is repeatedly reflected at the inner walls (23, 25, 26) of the interaction region (21 ) before it leaves the detector cell (4) again. In a preferred manner, the detector cell (4) is manufactured from silicon or quartz by photolithographic means.

Detector cell

A device for the electrophoretic separation of complex fluid substance mixtures comprises a channel system (21, 2, 22) for a carrier medium (C), an injection device (3) for the injection into the carrier medium (C) of a substance mixture (S) to be separated, and a separating path (2) for the separation of the substance mixture (S) in an electric field applied along the separating path (2). Downstream of the injection device (3) for the substance mixture (S) to be separated and at a distance therefrom there is provided a second separating path (4) for the further separation of the substance mixture (S) in an electric field applied along the second separating path (4). The second separating path (4) is inclined at an angle (.alpha.) with respect to the first separating path (2). The region of intersection of the first (2) and second (4) separating paths forms a second injection device (5) for injecting the partially separated substance mixture (S) into a second carrier medium (E). The fluid substance mixture (S) is injected into the carrier medium (C) in the first injection device (3) and is then separated in the electric field that is applied along the first separating path (2). The partially separated substance mixture (S) is then injected into the second carrier medium (E) downstream of the first separating path (2) and further separated into its components in the electric field applied along the second separating path (4).

Device and a method for the electrophoretic separation of fluid

A device for the separation of fluid substances, especially a capillary chromatographic separating device, is provided, which comprises a separating path in which a stationary phase is arranged and through which flows a mobile phase containing a sample to be separated into its components. The device also comprises means for transporting the mobile phase, and a detection device for detecting the separated components. The separating path is constructed in the form of an annular channel into which lead the inflow and outflow channels for the mobile phase and the fluid substance to be separated. In a very especially preferred variant of the invention the means for transporting the mobile phase are arranged inside the annular channel. In the described method of separating fluid substances the mobile phase together with the sample to be separated is circulated cyclically in a separating path constructed in the form of an annular channel. The circulation is preferably effected with the aid of transport means arranged inside the annular channel.

Device and a method for the separation of fluid substances

In an electrophoretic separating device, a channel defining a separating path is constructed in the form of a closed loop. A sample to be separated is introduced via a feed opening into an electrolytic carrier medium that is moved with the aid of an electric field through the channel, which is provided in the region of its ends with inlet and outlet openings for the carrier medium, and is separated into individual components by the electric field. The electric field is generated in the channel by connecting electrodes in the region of the inlet and outlet openings to different potentials of a voltage source. The procedure for carrying out the method according to the invention is distinguished especially by the fact that the carrier medium and the sample are moved along the substantially closed separating path formed by the channel which is constructed in the form of a closed loop.

Electrophoretic separating device and electrophoretic separating method

An apparatus (1) for processing or preparing liquid samples for a preferably quantitative chemical analysis, especially for flow-injection analysis, is, for the purpose of miniaturisation and reducing the necessary sample volume while at the same time reducing the analysis time, assembled from a set of plate-like components (8). Each of the components (8) includes channels to form pipe pieces (9) and/or branches (13) with orifices and/or values, for example non-return valves, and/or pumps (6,7) in order to be able to feed the carrier liquid and sample to a detector (3) in the desired manner. Depending on the purpose of the analysis, the components (8) with the pipes and functional parts contained in them may be stacked in varying number and/or sequence and/or angular orientation relative to one another and can be connected in a sealing manner in the operative position.

Apparatus for processing or preparing liquid samples for chemical

An apparatus (1) is used for the preparation or extraction of samples, especially for analytical purposes, from a liquid or using a carrier liquid, where only very little liquid and substrate is available or is to be used and where the sample separation is to be carried out very quickly. For this, the apparatus (1) comprises, etched or machined into a plate-shaped body (8), an essentially planar flow bed (10) which has inlets and outlets arranged at opposing ends in the direction of flow, and is covered and sealed on the processing side of the plate-shaped body (8) by a further plate, so that the flow bed (10), which has an approximately groove-shaped flat cross-section, is sealed on all sides. There extend parallel to the flow bed (10), but also machined or etched into the plate-shaped body (8), electrode chambers (13), which are connected by way of electrodes (13b) to a current source (13a) in order to generate an electric field in the flow bed (10) transversely to the direction of flow. The electrode chambers (13) are connected to the flow bed (10) by way of very fine channels (14) extending transversely to the direction of flow which permit voltage transmission but practically no transport of material, that is to say act in a similar manner to membranes. Etching technology permits a miniaturized construction of the apparatus (1).

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Bettingen, Switzerland

Andreas Manz