Abstract: A centrifuge rotor which makes use of a composite ring to support a segmented core body. The core body is segmented into sectors. The core segments are slidably coupled to a hub in a manner such that they can move radially relative to the hub upon centrifugation with substantially no radial tensile stress build up in the coupling between the hub and the core segments and within the segment cores. In another aspect of the present invention, to augment the segmented core rotor, hybrid composite sample holders are utilized to further improve overall strength-to-weight of the rotor. The holders comprise a metal portion and a fiber composite portion integrally molded.

Abstract: A probe washing apparatus including a probe having a tip and a wash collar having a bore coaxially aligned with the probe, the wash collar including ports for applying a vacuum and a wash liquid to the wash collar bore. The probe may be displaced vertically with respect to the wash collar to aspirate and dispense liquids, and the wash collar and probe are displaced together laterally. The steps of washing the probe tip include raising the probe to a position with the probe tip within the bore, applying vacuum to the bore, flushing the interior of the probe, and flushing the exterior of the probe.

Abstract: The present invention is directed to the implementation of a multi-port rotary valve in an automated chemistry processing instrument which reduces chemical reagent cross contamination and simplifies system design and control. One or more multi-port rotary valves are used in conjunction with isolation valves which are each dedicated for an associated reagent in the system. According to one embodiment of the present invention, the instrument utilizes a multi-port valve which defines several fluid branches each associated with a reagent. The valve has a common inlet and common outlet which are selectively brought into fluid communication with the branches in a controlled sequence. At each branch, there is a two-way three-port isolation valve which controls introduction of an associated reagent into the branch. When a branch is selected by the rotary valve, the reagent introduced into the branch is delivered out of the common outlet by the flow from the common inlet.

Abstract: The present invention is directed to a floating cap or spacer and centrifuge tube assembly which provide adequate resistance to the deforming forces exerted on it. The exterior wall of the tube stem is provided with an annular ridge and the support spacer is provided with an annular groove which mates with the ridge on the tube stem to form an interlocking coupling.

Abstract: Methods for controlling and varying electroosmotic flow in coated capillary electrophoresis columns under electrophoretic conditions are disclosed. The methods described herein involve varying the concentration of a multi-valent buffer compound in electrophoresis buffer compositions in order to control the electroosmotic flow in capillary columns having interior surfaces coated with charged organic coatings. Increasing the concentration of a multi-valent buffer compound which has a charge opposite the charge of the organic coating, in the electrophoresis buffer results in a decrease in electroosmotic flow. Decreasing the concentration of a multi-valent buffer compound results in an increase in electroosmotic flow. The ability to control electroosmotic flow provides enhanced resolution and optimizes separations of electrophoresis sample components.

Abstract: Improved fecal occult blood test having a matrix such as paper printed or impregnated with guaiac. The improvement comprises increasing the sensitivity while maintaining or improving the specificity of the test by employing an alcoholic-peroxide developing solution which contains an enhancing agent. The enhancers comprise phenolic type compounds such as esters of parahydroxybenzoic acids.

Abstract: Disclosed herein are variant versions of Streptolysin O produced by recombinant DNA techniques. In an embodiment, the variant is soluble upon expression and has a specific hemolytic activity of about 14 hemolytic units per milligram.

Abstract: A method for correcting for light scattering affects obtained from a sample to which a fluorophore has been added. In accordance with the invention, a sample to which a fluorophore has been added is irradiated with light in the adsorption band of the fluorophore such that the fluorophore emits light at a different intensity. By manipulating the pH of the sample, and obtaining both pre- and post-manipulation emission light intensity readings, the value of the reading attributed to "light scattering" can be determined, such that correction of an erroneous fluorescence reading can be obtained.

Abstract: A compact manifold for distribution of fluids (gas or liquid or combination thereof). The manifold has a block having fluid channels provided therethrough between two faces of the block. Against one face, a plate is fastened which swages ferrules between the plate and the block to tightly connect fluid conduits through the plate to the block. On the opposite face of the block, a manifold plenum is formed in a groove between a manifold plate and an o-ring. The o-ring is pressed against the manifold plate by a back plate and both plates are securely fastened onto the block such that the holes in the manifold plate are aligned with the fluid channels in the block. Checkvalves are positioned between the block and the manifold plate to prevent backflow. The above-mentioned components are positioned into their respective places and are secured upon the tightening of the fasteners. The manifold is configured with at least two plenums each having a group of distribution outlets.

Abstract: A centrifuge rotor overspeed protection system which can operate with rotors of at least two speed ranges. A set of coding elements are provided on the rotors coded to represent the actual maximum safe speed rating of the rotor. An additional set of coding elements coded to correspond to the maximum speed in the lower speed range are also provided such that the rotor can be operated at the maximum speed possible in a prior art centrifuge designed for operation in the lower speed range. The detection circuit for the coding elements automatically adjusts the detection threshold depending on the average values of the sensor output peaks corresponding to the codes.

Abstract: Disclosed herein are derivatives of Streptolysin 0 produced by recombinant DNA techniques. In an embodiment, the derivative is soluble upon expression and has a specific hemolytic activity of about 3.6.times.10.sup.4 hemolytic units per milligram.

Abstract: An initial rate photometric immunoassay method useful for detecting and quantifying analytes in various physiological fluids is disclosed. The method is carried out by combining in a liquid medium an undiluted sample of analyte-containing physiological fluid, such as serum, and an excess of an anti-analyte antibody. A substantially constant initial rate of increase of the liquid medium's turbidity, due to the resulting immunoprecipitation reaction, is measured in real time and compared to a calibration curve prepared from known analyte concentrations to detect and quantify the analyte. Detection and quantification of numerous analytes including, haptens, drugs and proteins, in a wide variety of physiological fluids can be rapidly carried out by the present method.

Abstract: A method of controlled centrifugation including automatic determination (before or during a centrifugation run) of the time to reach "completion" (within specified limits, depending on the criteria adopted) of a centrifugal separation. By simulation, the sample solute concentration distributions are determined and examined periodically. Centrifugation completion is deemed to have been reached based on certain predetermined criteria relating to spatial changes in the sample solute concentration distributions between successive examinations. The positions of the end points of the concentration distributions or band edges of the sample solutes (transitions from regions of sample solutes to regions of no sample solutes) are determined to facilitate resolving spatial changes of the concentration distributions.

Abstract: Disclosed herein are capillary columns for capillary electrophoretic analysis of sample constituents. In an embodiment, the columns comprise a bifunctional layer comprising a positively charged amine group adsorbed to the inner wall of the capillary and an active functional group; a gel composition; hydrophilic polymer; and a separation composition capable of being removed from the column, interspersed within the remainder of the column. The disclosed columns are particularly well suited for the analysis of surfactant: proteinaceous material complexes, nucleic acid sequence, and analysis of restriction fragments according to size.

Abstract: A method of programming a programmable controller in a manner by which a variety of menus, options, or questions seeking limited parameter answers are presented to the user; for example, setup parameters such as the type of labware, source and destination of reagent transfer etc. for conducting a particular biological and chemical assay experiments by an automated laboratory workstation. Software "templates" are used to focus the request for parameters from the user to tailor user needs to the laboratory workstation's capabilities. The software templates are designed to accommodate a wide variety of experimental setups in accordance with the setup parameters input by the user. By providing the parameters with the assistance of the templates, the user may program a complete set of instructions for conducting a biological or chemical assay. The instructions may include the time and method for undertaking the experiment.

Abstract: A valve block assembly with internal delivery channels and a common outlet channel is provided. Access of reactants to the delivery channels is controlled by diaphragm valves, preferably equipped with relief grooves to accommodate deformation of the diaphragm. Reservoirs feeding the delivery channels have an inert atmosphere controlled by pressurizing and venting channels in the valve block. Exposure of plastic tubing to oxygen is kept to a minimum. The assembly is particularly adapted for use in a DNA or protein sequencer to supply reactants without cross-contamination or oxidative decomposition.

Abstract: The present invention directed to a plug for sealing a centrifuge tube. The plug of the present invention is shaped and sized to provide an interference fit between the plug and the tube stem of the centrifuge tube. In the described embodiment, the plug is configured with a tapered body narrowing to a flared end. To facilitate the insertion and removal of the plug with moderate force, without compromising the restraining capability of the interference fit, the area of interference contact between the flared end and the filler stem is strategically reduced. An o-ring is provided in a annular groove around the tapered body. The flared end creates an interference fit with a tapered filler stem, whereby the plug is secured in the filler stem with a snapping action when the flared end of the plug extends into the tube beyond the tapered filler stem.

Abstract: A sample handling system suitable for use with a sample segment and a plurality of capillaries, including a rotatable and vertically translatable arm including an attachment portion to removably receive and retain the sample segment and a manifold adapted to removably retain the sample segment and the plurality of capillaries. The sample segment may be held by the attachment portion by the application of vacuum. Rotatable and vertical translation of the arm may be accomplished by a spindle and guide rails that are resiliently retained. The manifold may include a degassing reservoir and fluid manipulating valves retained by adapters configured to fail if external force is applied to the associated valve.

Abstract: Disclosed are reagents of methods for cleaving and deprotecting insolubilized and protected synthetic oligonucleotides. In a particularly preferred embodiment, the reagent comprises methylamine and t-butylamine.

Abstract: A centrifuge rotor lid assembly which includes a handle which allows convenient handling of a centrifuge rotor and facilitates releasing the lid from the rotor after centrifugation. In one embodiment, the lid is provided with a lid knob and a spindle knob in a coaxial sliding arrangement. The lid knob is used to tighten the lid on the rotor body and the spindle knob is used to tighten the rotor to the centrifuge drive spindle. The upper end of the inner knob is provided with a handle which extends perpendicular to the axis of the knob. This handle is used for lifting the rotor after the spindle knob has been unscrewed from the spindle and for unscrewing the lid knob. The lower end of the spindle knob has a pin which cooperatively engages the lower end of the lid knob when the spindle knob is lifted from the rotor and is turned in a direction to unscrew the lid knob.