Abstract: A means of sealing a centrifuge tube which makes use of the hydrostatic pressure of the sample solution contained in the tube to perfect a tight seal during centrifugation. The filler stem is plugged with a plug which is supported in the rotor cavity. The hydrostatic pressure forces the filler stem against the plug to effect a seal with a sealing force which is dependent on the hydrostatic pressure which is in turn dependent on the centrifugal force on the sample solution.

Abstract: A method of measuring and compensating stray light in absorbance analysis that use a multiple element array detector wherein one or more of the elements of the diode array are utilized to detect stray radiation in the absence of primary radiation including higher order diffracted radiation. In one aspect, the atmosphere is used to filter all primary radiation below a particular wavelength so that one or more array elements corresponding to detection below such wavelength can be dedicated to the detection of only stray radiation. Detection of higher order diffractions can be prevented by dividing the total spectrum into intervals and detecting these intervals in sequence. In another aspect, a diode array is designed to include additional elements along one side of the array outside the exposure of the primary radiation for the sole purpose of detecting stray radiation.

Abstract: An automated multi-purpose analytical chemistry processing center and laboratory work station having a movable table for supporting microtiter plates and other fluid receptacles, a movable arm, and a modular mobile pod affixed for reciprocal movement along the arm. The workstation combines into a single programmable system the capabilities for automation of a wide range of bioanalytical procedures including, not only sample pipetting, serial dilution, reagent additions, mixing, reaction timing and similar known manual procedures, but also programmable spectrophotometric measurements and other physical parameters, further processing based on these measurements and automatic data recording. The work station is adapted to transfer, dispense, and aspirate liquid from one location to another automatically in accordance with user programmed instructions.

Abstract: A monochrometer having a stray light trap which substantially directs stray light away from light of wavelength of interest and/or absorb the stray light so as to substantially reduce the stray light component in the light of interest. The monochrometer has internal surfaces each having one of several optical characteristics.

Abstract: A beverage serving set comprising a drinking straw and beverage container combination wherein the drinking straw is L-shaped having long and short parts, and the container has a guiding structure for maintaining the long part vertical in the container and the short part parallel to the lid of the container. The long part is slidable and rotatable in the guiding structure which may be an adapter depending from the lid or a guiding tube attached to the container wall. A clip is provided on the lid to securely hold the short part of the straw for storage, and in addition a cap may be provided at the clip for capping the end of the short part of the straw.

Abstract: An automated multi-purpose analytical chemistry processing center and laboratory work station having a movable table for supporting microtiter plates and other fluid receptacles, a movable arm, and a modular mobile pod affixed for reciprocal movement along the arm. The work station combines into a single programmable system the capabilities for automation of a wide range of bioanalytical procedures including, not only sample pipetting, serial dilution, reagent additions, mixing, reaction timing and similar known manual procedures, but also programmable spectrophotometric measurements and other physical parameters, further processing based on these measurements and automatic data recording. The work station is adapted to transfer, dispense, and aspirate liquid from one location to another automatically in accordance with user programmed instructions.

Abstract: A method and apparatus for improving signal to noise in an electropherogram acquired by electrophoresis. The migration time is remapped by binning the data with respect to migration time to improve signal to noise and peak resolution. The data points of the electropherogram are pooled into variable size bins, each corresponding to a number of time intervals. The sizes of the bins increase with migration time. To further improve signal to noise and peak resolution, the binned data is filtered by Fourier transformation. The present invention allows for accurate determinatiion of DNA sequences.

Abstract: A robot gripper module having a housing pivotally mountable to an end of a robot arm. The housing encloses a first motor for pivoting the housing about a pivot joint, and a second motor operating a rack-and-pinion gear arrangement for extending and retracting fingers. Two opposed groups attached to a rack on opposite sides of a pinion gear. Turning the pinion gear causes the fingers to move toward or away from one another. The motors which may operate independently of the robot arm, may be either servo or stepper motors. The gripper module provides additional degrees of freedom from that of the robot arm, enabling it to work with many kinds of robot arms.

Abstract: A electrophoretic system in which nonconductive members are strategically positioned in the electrolyte tank to selectively affect the electric field of electrodes so as to obtain a desired electric field for efficient separation. The size, shape and location of the nonconductive members are selected using a electric potential analysis.

Abstract: A hybrid centrifuge rotor having a rotor core surrounded by a prestressed anisotropic reinforcement ring is disclosed. The rotor core may be made from aluminum and an anisotropic reinforcement ring may be a cylindrical filament wound ring, made from graphite fiber and epoxy resin. The rotor core is manufactured to have a nominally greater diameter than the inner diameter of the reinforcement ring. This rotor core, during the manufacturing process, is subjected to a cryogenic environment where the diameter is shrunk down so that the rotor body may fit and telescope within the reinforcement ring. The rotor body core and reinforcement ring assembly, upon attainment of ambient temperatures, have an interface fit wherein substantial outward force from the rotor body core prestresses the reinforcement ring so that a light weight and strong centrifuge rotor is disclosed.

Abstract: An automated chemical conversion unit for use in a peptide/protein sequencing process. The improved conversion methodology decreases the time necessary for the conversion reaction chemistry of the specific derivative of the sequenced amino acid to a more stable form. The conversion reaction is designed to be performed directly in a fraction collector tube which operates in one embodiment in conjunction with a thermoelectric temperature element to allow utilization of different temperature levels for different amino acid derivatives.

Abstract: Solid phases such as capillary tubes or solid supports used in chromatography, and in particular electrophoresis, are treated with oxidizing or reducing agents as needed to maintain or restore surface electrical charges or the lack thereof, which become modified during electrophoresis as a result of action by system components in the separation medium or the solutes themselves. The treatment is used as a means of achieving reproducible electroosmotic bulk flow when desired or suppressing unwanted electroosmotic flow arising due to the accumulation of charges on the surface. The result is improved reproducibility of retention times and component separation.

Abstract: A check valve cartridge insertable into a valve housing which is adapted to couple to a pump fluid head. The check valve cartridge has a fluid pathway therethrough with a desired direction for fluid flow. The cartridge utilizes a ball-seat assembly to control the direction of fluid flowing through the cartridge to the desired direction. The ball-seat assembly includes a rigid seat which is compliantly supported within the cartridge by thin compliant spacers. The check valve cartridge further has deformable seals which partially fit within the opposed ends of a cartridge body and are adapted to cold flow and seal to a surface when subjected to a force. One of the deformable seals is adapted to seal against a surface of the pump fluid head and has slidably mounted over its end a rigid ring which constrains the cold flow of the end of the seal that seals to the pump fluid head. The check valve cartridge may be designed to be used for inlet and outlet check valves.

Abstract: Aqueous buffer solutions for use in an ion exchange amino acid analysis system compounded so that it is non-corrosive to the stainless steel components of such a system while achieving high resolution and short analysis times in separation of the various amino acids in a sample mixture. The aqueous buffer preferably comprising a mixture of salts free of halogen ions but containing nitrate ions which tend to passivate stainless steel preventing corrosion.

Abstract: A process and apparatus for predicting the time and position dependent concentration of macromolecules of differing species in a gradient forming solution during centrifugation is disclosed. A mathematical model of the time dependent behavior of gradient forming solutes in a centrifugal field, based upon the underlying physical principles governing sedimentation and diffusion is formulated. The simplifying approximation is made that the wall effects may be ignored, and that the transport of solute may be treated as a one dimensional process with forces dependent only upon the radial distance. A sedimentation diffusion (Lamm) equation in one dimension is numerically integrated. The sedimentation diffusion equation (Lamm equation) for each macrosolute is solved concurrently with that for the gradient forming solute, utilizing the experimentally based density dependent sedimentation coefficient. The equations are solved for incremental time periods for the centrifuged samples in successive radial segments.

Abstract: A detector for detecting the presence of an electrically conductive sample solution in a sample injection metering valve by electrical sensing the leading edge of the sample solution, wherein the amount of sample solution in excess of the metered amount required to cause detection is minimized. A conductive probe is positioned on the valve body just downstream of the sample metering passage of the valve, the probe being electrically insulated from the valve body. The probe and valve body form electrodes which will detect the arrival of the leading edge of a conductive sample solution which completes a conductive circuit between the electrodes.

Abstract: A thermoelectric cooling design of the type having a nonconducting substrate mounting thermoelectric coolers is improved. Provisions for a flexible can and improved heat dissipation from the thermoelectric coolers are provided. For improved thermal response, the refrigerated vacuum can is provided with thin walls of high purity aluminum with the result that deformation of the wall surface, especially the bottom wall surface can occur both with respect to installation. A plurality of can heat sinks are placed on the walls of the can to form a unitary and locally rigid side wall to the can at the point of attachment. At least one thermoelectric cooler is communicated to the can heat sinks at a first side for receiving heat energy from the can. A second discharge heat sink is communicated to each thermoelectric cooler for dissipating heat energy from both the can and the thermoelectric cooler.