Abstract: A centrifuge includes a drive shaft-to-hub coupling assembly for providing vibration damping that is selective to torsional damping over lateral damping. An impeller is fixed to a drive shaft and a receiver is fixed to a rotor-bearing hub. Relative rotation between the impeller and the receiver is restricted to compression and decompression of elastomers trapped between teeth extending from the impeller and from the receiver. The elastomers function to damp torsional vibrations and torsionally induced lateral vibrations. The receiver is prevented from becoming axially misaligned with the impeller by including one or more rigid annular bushings that maintain the distance between the hub and the drive shaft, thereby preventing the elastomers from being deformed in a manner which would damp lateral vibrations. The annular bushing is mounted to allow relative rotation between the impeller and the receiver.

Abstract: The present invention makes use of a single detector to monitor several process functions, e.g. reaction efficiency, reagent flow rates, the presence of empty reagent reservoirs, the absence of a chemical reactor column in the system, blockage of flow system, etc., at a single location in the flow system. In accordance with the detection scheme of the present invention, only one detector is required to accomplish the same, if not more, functions as many detectors in the prior art instruments. In the described embodiment, an optical detector is positioned downstream of a chemical reaction chamber. This detector monitors the effluent from the reaction chamber to monitor the reaction efficiency. It also monitors the system functions upstream of the reaction chamber. System flow rate is monitored by detecting the presence of a gas bubble which has been introduced into the system at a known instance.

Abstract: Coated capillary electrophoresis columns and methods for their use in electrophoretic separations are disclosed. The coated capillary columns include a length of tubing having an interior surface having an interconnected polymeric coating. The interconnected polymeric coating includes a hydrophobic polymeric functionality covalently bound to the interior surface and a hydrophilic polymer interconnected with the hydrophobic polymeric functionality. Exemplary columns are prepared by causing a Si-OH reactive compound, having a hydrophobic polymeric functionality, to react with Si-OH functionalities on the interior surface of capillary columns. Then causing a hydrophilic monomer to polymerize in contact with the hydrophobic polymeric functionality forms a coating of interconnecting hydrophilic and hydrophobic polymers.

Abstract: An assembly for transferring rotation from a centrifuge drive system to a centrifuge rotor includes a hub that is connected to the drive system for rotation about an axis. A sleeve member is attached to the hub in a position to support the centrifuge rotor. The sleeve member is formed of a material having a low coefficient of friction and is positioned to reduce the likelihood of rotor-to-hub lock. The resistance of the sleeve member to wear and to the absorption of foreign matter are also important in the selection of a material for forming the sleeve member. An acetal-based compound is preferred. By connecting the sleeve member to the hub such that the exterior surface of the sleeve member is raised relative to the surface of the hub, rotor-to-hub contact is reduced, thereby further reducing the risk that the rotor and the hub will become locked to one another.

Abstract: A closure and device for use with a closure, the closure including a first member having a beveled edge, a second member having an undercut edge, and optionally a base member to which the second member is fixed. The first member is adapted to be received with the beveled edge retained by the undercut edge. A test device may include such a closure and may also include a hinge between the first and second members. Test elements, such as a chromatographic medium and absorbent pads, may be disposed on the first member and/or the base member and may be brought into opposition by closing the first member with the closure.

Abstract: Disclosed herein are buffers and methodologies for the capillary zone electrophoretic analysis of hemoglobin and the variants of hemoglobin. In a particularly preferred embodiment, the buffer comprises at least about 100 mM of barbituric acid, derivatives of barbituric acid, combinations of barbituric acid and derivatives of barbituric acid, and combinations of the derivatives of barbituric acid, and has a pH of at least about 8.0.

Abstract: A method for making a valproic acid derivative comprising a functionalized spacer arm attached to a .delta. carbon atom of a valproic acid molecule is disclosed. The method proceeds by attaching a spacer arm joined to an inorganic moiety to a valproic acid precursor to make an alkylated compound, derivatizing the alkylated compound in a liquid medium to make the valproic acid derivative, and then separating the valproic acid derivative from the liquid medium. The valproic acid derivative can be used to make an immunoreactive valproic acid conjugate.

Abstract: Procedures such as oligonucleotide, peptide or protein syntheses or sequencing, or immunological or other biospecific assays involving long sequential series of chemical reactions are performed on a solid phase support retained in a pipette tip. The manipulations involved in bringing the solid support into contact with the various reagents or reactants involved in the procedure are performed and controlled by automated instrumentation.

Abstract: A method useful for determining the content of a first hemoglobin in a blood sample which also contains other forms of hemoglobin is based on capillary electrophoresis. In the method, a specific binding partner to the first form of hemoglobin is added to the sample, and the sample is then subjected to capillary electrophoresis. The method is particularly suited for the determination of the percentage of Hb A.sub.1c in a blood sample using anti-Hb A.sub.1c antibody.

Abstract: A method and system of determining an operation parameter for a centrifuge includes measuring one or more physical characteristics of a rotor interchangeably supported by a rotor drive. In the preferred embodiment, windage is measured at a first rotational speed and a speed-dependent signal is generated to adjust a vacuum system based upon changes in rotational speed of the rotor. Changes in windage may also be used as a basis for adjusting a refrigeration circuit. Either as an alternative or in addition to monitoring windage, the moment of inertia can be measured and used to adjust adaptive circuitry. For example, the drive circuitry may be adjusted based upon a determination of inertia as the physical characteristic of interest. The method and system isolate inertia and windage as the main forms of resistance to acceleration of the rotor.

Abstract: An automated method and apparatus for performing biopolymer synthesis on a two-dimensional support surface whereby a two-dimensional matrix or array of biopolymers are obtained on the surface. An applicator in the form of a thick plate having in a surface at least one cavity in the form of an open chamber or channel is used for applying reagents to the surface of a solid phase support material. The applicator is positioned over the solid support material with the surface having the cavity sealed against the material surface. For each cavity, reagents for synthesis are introduced sequentially into one end of the cavity and collected from the other end of the cavity. A one-dimensional array of biopolymers are thus formed on the support material, where each element of the array contains a population of biopolymers having identical sequence.

Abstract: An automated analytical system module design essentially electrically isolates modular elements within the analyzer system with inter-module communications provided via packet-based communications. The modules may include a motor controller which estimates motor temperature to enable high initial torque with motor failure prediction and detection. The modules in such a system can be identified on serial communications loops by a module reset and count-off process.

Abstract: Disclosed herein are protecting groups for exocyclic amino groups of the bases adenine, guanine and cytosine for use in the synthesis of oligonucleotides, the protecting groups being represented by the formula: --CO-- (CH.sub.2).sub.0-9 --CH.sub.3. In a particularly preferred embodiment, the base cytosine is protected with acetyl (--CO--CH.sub.3), and the oligonucleotide incorporating said protected cytosine is subjected to a cleavage/deprotection reagent comprising at least one straight chain alkylamine having from 1 to about 10 carbon atoms.

Abstract: Diluents and methodologies for determining the concentration of total calcium in a clinical sample (e.g. whole blood, sera plasma urine cerebro spinal fluid) containing protein-bound calcium are disclosed. Methodologies include the steps of: (a) admixing the sample with a diluent, the diluent including effective amounts of a pH buffer and at least two agents capable of complexing free calcium in the sample, where the agent-calcium complex association constants ("log K" in base 10) each have a range from about 1.5 to about 7.0; and (b) contacting an aliquot of the diluted sample with a calcium-specific ion selective electrode. The response of the calcium-specific ion selective electrode is an indication of the concentration of total calcium in the sample.

Abstract: A novel bidentate conjugate has two different chemical moieties, or bidentate members, attached through an adequate spacer moiety. Each bidentate member acts as a small molecule ligand and is capable of specifically binding to a different macromolecular substance. The bidentate members are relatively small molecules, usually less than about 7,000 Daltons in size. The spacer moiety is selected so that both bidentate members can simultaneously bind to their respective specific binding partners. Where the specific binding partners are multivalent, large complexes can be formed. The formation of these complexes can be inhibited by the presence of an unconjugated monovalent bidentate member, such as free analyte from a test sample. The bidentate is of particular use in turbidimetric or nephelometric inhibition immunoassay procedures.

Abstract: The filling of an internally coated capillary with a gel in its polymerized state without damaging the gel. The coating prevents bonding of the gel to the inside of the capillary, The gel comprises up to 6% acrylamide and 0-5% crosslinker. The gel can be advantageously and conveniently used in automated electrophoresis systems for automatic replacement of spent gel.

Abstract: The present invention is directed to a synthesis reaction column which can be conveniently implemented in post synthesis procedures. The reaction column is configured to allow easy connection to a syringe and post synthesis reagent container without requiring connection adapters.In one embodiment, the reaction column configured in the form of a cylindrical column containing the solid-phase support and having a narrow bore tube extending at one end. The tube functions as a piercing tip for accessing a septum sealed vial containing post synthesis reagent. In another embodiment, the reaction column is configured in the form of a cylindrical barrel enclosing the solid-phase support and having a threaded mount at one end. To complement the reaction column for post synthesis procedures, a vial having a complementary threaded mount at the opening is used for containing a reagent. This vial is conveniently threaded onto the end of the barrel without adapters.

Abstract: A capillary and capillary retaining system including a capillary assembly having first and second end holders. The first and second end holders are adapted to be received by first and second retainers. The first end holder may include protruding portions and the first end retainer includes clips to receive the protruding portions. The second end holder may include opposite recesses and the second retainer is adapted to receive optical cables that are received within the recesses to retain the second end holder. Locks retained by the second end retainer cooperate with grooves in the optical cables to retain the optical cables.

Abstract: A device for centrifugally separating a sample includes a housing which defines an enclosed chamber from which gas is evacuated via an evacuation port protected by a spinning rotor. The evacuation port is preferably located proximate to the axis of rotation of the rotor and within the interior of the rotor. A drive shaft connects the rotor to a motor positioned outside of the chamber. An annular sleeve having an inside diameter greater than the diameter of the shaft extends coaxially along the drive shaft into the chamber. The outlet of the gap between the drive shaft and the annular sleeve defines the evacuation port. A hub is fixed to the upper end of the drive shaft and includes a downwardly depending skirt that has an inside diameter greater than the outside diameter of the annular sleeve. Gas evacuation from the chamber is initially in an upward direction along the gap between the hub skirt and the sleeve and in a downward direction from the evacuation port to a vacuum pump.

Abstract: A centrifuge rotor and method for gradient density separation which supports a generally cylindrical volume of sample solution with its axis inclined to the spin axis at an angle which is optimized for maximum separation efficiency while reducing contamination by undesirable centrifugates upon reorientation of the desirable centrifugates. .Iadd.The sample solution is contained in a centrifuge tube which is closed at its top end by a top portion which is supported by a support cap. The undesirable centrifugates are pelleted to the end corners of the inclined centrifuge tube. The rotor and method are particularly adapted, for example, for separation of nucleic acid into plasmid DNA and chromosomal DNA by density gradient centrifugation. .Iaddend.The optimum angle is determined based on the relationship .theta.=Tan.sup.-1 (D/15L).sup.0.5 where D and L are respectively the diameter and length of the cylindrical volume of the sample solution and .theta. is the angle of inclination.