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.

Abstract: A electrophoresis column having on-column means and a method for concentrating analytes of interest in a sample prior to electrophoresis. The column comprises a section having the concentrating means upstream of a capillary section. A sample is flowed past the concentrating means which immobilizes the analytes of interest thereby concentrating the analytes of interest in the section. Thereafter the analytes are released from the concentrating means for carrying out electrophoresis.

Abstract: The present invention is directed to a technique that provides enhanced separation resolution in electrophoresis. This technique involves the use of a time-varying field strength, which may be progressively increasing or decreasing, constant or otherwise, as a function of time. The shape of the field strength with respect to time may be continuous or stepwise over time, monotonic or otherwise.Because the mobility of different size species is a function of the applied electric field, the use of a nonuniform (time varying) electric field increases the resolving power of electrophoresis. This technique has been found to provide enhanced resolution of double-stranded DNA molecules in capillary polyacrylamide gel electrophoresis. It has been found that enhanced separation of DNA restriction fragments of 1 to more than 1000 base pairs in size has been achieved employing the technique of the present invention.

Abstract: A method and apparatus for generating scintillation pulse height distribution spectrum with respect to a square root representation of pulse height. Pulse height data are pooled into variable size windows of which the average energy level is approximately proportional to the square of the corresponding window number. The square root representation is accomplished by choosing the size of each window according to an arithmetic series of a constant difference between windows.

Abstract: A reciprocating fluid pump having a shaft which dynamically self-corrects angular misalignment between the shaft and its drive mechanism during reciprocative motions. A thrust bearing is utilized to take up axial loading of the shaft to allow the shaft to freely rotate on its supports.

Abstract: The present invention provides processes for isoelectric focusing ("IEF") and associated detection, which incorporates a dynamic means of electroosmotic flow ("EOF") control during IEF and/or after IEF to effect solute mobilization. In accordance with the present invention, the EOF control during IEF and/or solute mobilization after IEF are accomplished by applying an external electric field, relative to an internal electric field, to modify the electroosmotic flow in the capillary. This can be done by disposing a conductive member at one or more locations outside and along the buffer column in the capillary. The conductive member may be statically charged or caused to conduct a current to create the external required electric field. The applied external electric field may be adjusted, relative to the internal electric field, during IEF as necessary to reduce or completely suppress EOF to prevent flow of the buffer.

Abstract: A method of positively deciphering a DNA sequence of a sample by comparing data of two electropherograms obtained from separate electrophoresis of products from two complete sequence reactions of the same sample, whereby dideoxynucleotide terminators of different but matched concentration ratios are employed for the two reactions. The sequencing chemistry is chosen to result in terminator-concentration dependent in peak intensity in the electropherograms. By appropriately choosing the matched concentration ratios of the terminators used in the two sequence reactions, ambiguities in the discrimination of the peaks in the result of one sequence reaction can be resolved by comparing the result of the other sequence reaction. The sequence of the sample can therefore be deciphered to a high degree of accuracy. For fluorescence detection of electrophoresis of the sequence reactions, three ddNTP terminators and one fluor are included in the sequencing chemistry of each reaction.

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: An apparatus xxx method of aligning a capillary with respect to a radiation source. More particularly, the capillary is aligned with a laser beam for laser induced fluorescence detection. The light reflection/scatter pattern of the laser beam originating from the capillary wall is utilized to determine optimum alignment. Photosensors may be implemented to detect the scatter pattern which represents optimum alignment. For dynamic alignment during electrophoresis, the photosensors provide feedback to a controller which controls a positioning mechanism for alignment of the capillary.

Abstract: A centrifuge rotor having a balancing ring integrally formed with and raised from the upper surface thereof is manufactured by removing material from the ring to balance the rotor in the upper plane. The balancing ring is on the same radius as the rotor tube cavities and of width less than the diameter of said cavities such that the ring, when the tube cavities are drilled, is broken into segments of precisely known area which make the amount of material to be removed to balance the rotor readily determinable.

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 cartridge for holding a capillary for electrophoresis. The cartridge has a body defining a passage along which the capillary is threaded. Exits are provided on the body for extending the ends of the capillary to access external fluid sources. The same cartridge may be used for different lengths of capillaries. An aperture is provided on the cartridge for optical detection of electrophoretic separation in the capillary held in the cartridge. The cartridge may include a hollow space defined about the capillary for circulating coolant fluid.

Abstract: A flexible member which extends about foot high is transversely mounted at the foot end of the flat mattress for supporting bedclothes at the foot end area to reduce the pressure on the upward pointed toes when a person sleeps face-up. Detachable and/or pivotable mounting means allow the flexible member to be mounted on either side and on either end of said mattress. Further, provision may be made to allow the flexible member to be selectively positioned along the length of the mattress. The flexible member is provided with electrical heating device and thermostat control for warming up the feet area.

Abstract: Method and apparatus for controlling the angular velocity of a centrifuge tube containing a solute and a solvent to obtain desirable sedimentation behavior and/or diffusion behavior of the solute within the tube during centrifuge operations. In one embodiment, the angular velocity is maintained at a near-maximum value until just before precipitation of a solute component is reached within the tube. The tube angular velocity is then reduced as a function of time so that critical precipitation is approached but never occurs in the tube as the centrifuge process continues. In other embodiments, the net flux of solute particles into a given volume element of the centrifuge tube, or the ratio of net fluxes of two or more solutes into a predetermined volume elements, is caused to be a prescribed function of time. One application of this method is minimization of the time required to obtain a desired density gradient separation by a centrifuge process.

Abstract: A reciprocating shaft which dynamically self-corrects angular misalignment between the shaft and its drive mechanism during reciprocative motions. A thrust bearing is utilized to take up axial loading of the shaft to allow the shaft to freely rotate on its supports.

Abstract: A redundant safety lock for securing a centrifuge lid in its closed position. The lock includes a disc having an aperture through which a striker on the lid can be inserted in an unlocked position. The disc is rotated to a locked position such that the striker cannot be withdrawn through the aperture to open the lid. The weight distribution of the disc is substantially symmetrical about its center of rotation. The disc is therefore less susceptible to dislodging form its locked position upon perturbation from shock experienced.

Abstract: A detection and quantification technique for radioisotope labeled components separated in a capillary separation channel. The section of the separation channel containing the separated components is significantly cooled to substantially eliminate diffusion of the components while detection is being carried out. The section can be frozen and autoradiography technique or solid state electronic imaging technique can be utilized to obtain an image representative of the relative amounts of separated components.

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 procedure 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 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.