Abstract: The invention relates to a rotary drive adapted for creating liquid flow in rotatable microfluidic discs. A rotary drive for spinning a disc shaped substrate having microfluidic structures formed therein for the flow control of microliter and/or nanoliter volumes of liquid by centrifugal force is suggested, comprising a motor with a spindle having an axis of rotation. A rotary member is connected for rotation with the spindle and driven for rotation relative to a stationary member, the rotary member being formed with a top plane having a centering guide for receiving the disc so as to force a symmetry axis of the disc into alignment with said axis of rotation. A vacuum source is connected with the stationary member and communicating with the rotary member or a part thereof rotating with the rotary member for applying sub-pressure to the disc when spinning the disc about its symmetry axis. Preferably, the rotary member is journalled for contact-free rotation relative to the stationary member.

Abstract: The invention relates to an apparatus for sample preparation and/or sample delivery for an injection system of a chromatograph, having a magazine (1), which can be moved in steps, for juxtaposed sample tubes (2), and having a lifting device (6) which can be moved between two end positions perpendicular to the transport direction of the magazine (1) via a motor (11) and bears a gripper (7) for a sample tube (2), as well as having a transfer device for a sample tube (2), the lifting device comprising at least one telescopic threaded cylinder (8) which bears the gripper (7) and has a plurality of nested threaded cylinders with an inner threaded cylinder (8a) and an outer threaded cylinder (8d) of which one is arranged non-rotatably relative to the magazine (1), while the other can be rotated by the motor (11).

Abstract: Method and apparatus for generating an acid or base, e.g. for chromatographic analysis of anions. For generating a base the method includes the steps of providing a cation source in a cation source reservoir, flowing an aqueous liquid stream through a base generation chamber separated from the cation source reservoir by a barrier (e.g. a charged membrane) substantially preventing liquid flow while providing a cation transport bridge, applying an electric potential between an anode cation source reservoir and a cathode in the base generation chamber to electrolytically generate hydroxide ions therein and to cause cations in the cation source reservoir to electromigrate and to be transported across the barrier toward the cathode to combine with the transported cations to form cation hydroxide, and removing the cation hydroxide in an aqueous liquid stream as an effluent from the first base generation chamber. Suitable cation sources include a salt solution, a cation hydroxide solution or cation exchange resin.

Abstract: Techniques for the delivery of metered amounts of liquid material include the use of a pin, such as an optical fiber. A sample of the liquid material may be placed on the tip of the pin for delivery to a target area, such as a specific location on a microarray, in a contactless manner. Light transmitted through the pin may be detected to facilitate accurate measuring of the pin's position.

Abstract: This invention is a method and device for use with multi-dimensional chromatography that utilizes partial modulation. An analyte-bearing sample is subjected to a first dimension of chromatography. Thereafter the separated analyte-bearing sample is diluted with a modulated second carrier such at the analyte-bearing sample is not stopped or its temperature altered. The partially modulated analyte-bearing sample then feeds into a secondary column where the analyte-bearing sample is further separated.

Abstract: A device for extracting an analyte from a sample matrix comprises a sorption vial with a conically shaped interior surface, which is coated with a sorbent material. A method for extracting an analyte from a sample matrix includes retaining the sorption vial within a sample vessel with the sorbent coating exposed to the sample matrix contained in the sample vessel. After the analyte is collected in the sorbent material, the sorption vial may be removed from the sample vessel and sealed, or a small amount of elution solvent may be added to the sorption vial before sealing. The sorption vial containing the analyte may then be stored or transported to a lab for further analysis.

Abstract: An apparatus is provided to automatically cover and uncover crucibles according to a predetermined procedure in a proximate analyzer. A series of crucibles mounted in a first carousel is heated in a furnace. A second carousel mounted above the first carousel holds crucible covers. A mechanism synchronizes the movements of the carousels so that the heated crucibles are automatically covered and uncovered at the appropriate times during the analysis with a corresponding cover by lowering or raising the second carousel. The movements of both carousels are automatically controlled so that at appropriate points in the testing cycle they rotate simultaneously about a common central axis and a crucible is deposited on a weighing platform by controlling the vertical motion of the entire carousel apparatus. The crucible is weighed either with or without a crucible cover depending on the stage of the analysis without the need of manual intervention.

Abstract: An improved cartridge for holding a fluid sample with a small volume is disclosed herein. The cartridge has a test chamber and a vestibule through which the test fluids are inserted into the test chamber. Improved grips are flared-out to aid manipulation. The handle portion is reinforced to prevent flexing, and a prefabricated trough along the edge of the land surface prevents introduction of the adhesive into the region for analysis. The cartridge has a stopper having a dual sealing mechanism, which seals the test chamber inlet between the vestibule and the test chamber, and the mouth of the vestibule so that when the stopper is in place, the test chamber is closed to the admission of air or other contaminants. The vestibule is similarly closed against escape of the overflow from the test chamber. The stopper is composed of a single elastomer. An improved locking mechanism has two flexible walls on either side of the handhold that locks into their respective keepers on the cartridge to provide a secure lock.

Abstract: The sampling pipette comprises a body; an arm movable relative to the body parallel to a longitudinal direction of the pipette in order to eject a cone fixed to the body; and a button for controlling movement of the arm. The pipette is arranged in such a manner that the button applies sliding thrust on the arm while the arm is moving relative to the body.

Abstract: A capillary 1 is moved to a position above a vessel 17 having a solution 15 stored therein. Then, the vessel 17 is raised while the inside of a tube 5 is opened to an ambient pressure until one end 1a of the capillary 1 is dipped into the solution 15. The solution 15 is introduced into the capillary 1 by means of capillarity. Next, the vessel 17 is lowered, to thereby removing the end 1a of the capillary 1 from the solution 15 stored in the vessel 17. Subsequently, the capillary 1 is moved to a position above a vessel 19 to which the solution 15 is to be transferred. Then, the tube 5 is connected to a pressure mechanism, thereby pressurizing the inside of the capillary 1 from another end 1b thereof. The solution 15 in the capillary 1 is then discharged to the vessel 19.

Abstract: A system for automatically performing liquid chromatography analysis of low volume liquid chemical samples at nanosecond flow rates using an analysis column that integrates a pre-concentration trapping column and a chromatography separation column terminating at an electrospray nozzle of an online mass spectrometer. The analysis column consists of a capillary having an inside diameter of between 75 and 125 microns packed throughout with a porous bed of micron particles. A branch outlet positioned 10 to 16 centimeters upstream from the nozzle divides the analysis column into an upstream pre-concentration trap and a downstream separation column. An autosampler delivers low volume liquid samples to the upstream inlet via a two-position valve. Feed connections couple the autosampler to upstream inlet when the valve is open to inject a liquid sample into the pre-concentration trap at a maximum loading flow rate in the range from 0.5 to 50 microliters/minute.

Abstract: A method to collect a plurality of target zones from a plurality of channels. The method includes introducing a plurality of compound mixtures into a plurality of microchannels on a microfabricated chip or a capillary tube. Optical signal measured at a detector window provides a signal of the position of a target zone. When a target zone has migrated to the location of a detector window, the detector senses an optical signal from the target zone and signals the system to disconnect a driving force from that channel. Once a plurality of zones in a plurality of channels are aligned, the driving force is reconnected and the zones are coeluted into a collection container.

Abstract: A pipette tip and mounting shaft combination in an air displacement pipette, the combination comprising a pipette tip mounting shaft having a radially stepped exterior comprising adjacent substantially cylindrical portions of different diameter and an annular sealing zone including an annular edge seal at an outermost edge of a radially extending shaft transition, a pipette tip including an annular sealing region having an inner sealing surface on a sidewall of the tip which in the sealing region is sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing zone when the sealing zone penetrates the sealing region, and axial penetration limiting means for limiting penetration of the shaft into the tip to limit axial contact between the sealing region and the sealing zone to a narrow annular band comprising the annular edge seal.

Abstract: Method and apparatus for generating an acid or base, e.g. for chromatographic analysis of anions. For generating a base the method includes the steps of providing a cation source in a cation source reservoir, flowing an aqueous liquid stream through a base generation chamber separated from the cation source reservoir by a barrier (e.g. a charged membrane) substantially preventing liquid flow while providing a cation transport bridge, applying an electric potential between an anode cation source reservoir and a cathode in the base generation chamber to electrolytically generate hydroxide ions therein and to cause cations in the cation source reservoir to electromigrate and to be transported across the barrier toward the cathode to combine with the transported cations to form cation hydroxide, and removing the cation hydroxide in an aqueous liquid stream as an effluent from the first base generation chamber. Suitable cation sources include a salt solution, a cation hydroxide solution or cation exchange resin.

Abstract: The movement and mixing of microdroplets through microchannels is described employing silicon-based microscale devices, comprising microdroplet transport channels, reaction regions, electrophoresis modules, and radiation detectors. The discrete droplets are differentially heated and propelled through etched channels. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device.

Abstract: A method for producing arrays by spacing a dispenser a distance from a surface of a support, dispensing a volume containing a compound in a single coupling step of less than 5 nl to occupy a localized area of less than 1 cm2 of the surface of the support, allowing the compound to bind directly or indirectly to the support and repeating the steps to produce an array of at least 100 ligands at a density of 1000 per cm2 or greater.

Abstract: A method for determining the length and velocity of single elongated macromolecules is disclosed. In particular, the present invention relates to methods and apparatus for determining the velocity of elongated polymeric molecules moving relative to one or more detection stations, as well as to methods and apparatus for determining the length of such molecules and the distance between landmarks that may be present on such molecules. The invention makes use of time correlated measurements of signal amplitude profiles that result from interactions between each detection station and portions of each macromolecule.

Abstract: A piston seal assembly for a pipette includes an O-ring having radially inner and outer surfaces and axially separated first and second surfaces. A seal includes a radially extending rim portion having axially separated first and second surfaces and an axially extending sleeve portion forming an opening. A seat includes an axially extending indexing portion and a radially extending engagement portion forming an opening and having axially separated first and second surfaces. The seal is positioned such that the pipette piston extends through the opening and the radially inner surface of the sleeve portion slidably engages the piston. The seat is positioned such that the piston extends through the opening, the first and second surfaces of the engagement portion engage the second surface of the rim portion and an end of the spring, respectively, and the radially outer surface of the indexing portion engages the inner surface of the pipette body.

Abstract: The movement and mixing of microdroplets through microchannels is described employing microscale devices, comprising microdroplet transport channels, reaction regions, electrophoresis modules, and radiation detectors. The discrete droplets are differentially heated and propelled through etched channels. Electronic components are fabricated on the same substrate material, allowing sensors and controlling circuitry to be incorporated in the same device.

Abstract: A portable system for analysis of blood or other bodily fluids removable from a patient is disclosed. The system includes a temperature sensing device and a temperature control circuit. The temperature sensing device senses a temperature of a surface of a sensor substrate of a cartridge having an electrical heater device without direct contact with the cartridge or direct exposure to the heating device. The temperature sensing device also generates an electrical signal related to the sensed temperature. The temperature control circuit controls an electrical input to the heater device based on the sensed temperature and a designed control temperature.