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.

Abstract: A liquid degasser includes a debubbler chamber connected in a line from a reservoir. Degassed liquid is fed from the chamber via a sensing electrode back to the reservoir. Fluid is drawn into the debubbler chamber at a first volume of flow rate, and gas is removed at a second, slower volume of rate. Degassed liquid is pumped from the base of the chamber through the sensing electrode and fed back to the reservoir. The gases from the debubbler chamber are returned directly to the reservoir.

Abstract: A sample counting support for scintillation counting of a radioactive labeled sample comprises a base material covered with a thin layer of dry solid scintillator in a substantially permanent form so that the support may receive the sample and produce light emissions in response to particules emitted by a radioactive substance labelling said sample.

Abstract: A liquid level sensing system comprising a probe and a reactive element carried by the probe. The reactive element forms a portion of a tuned circuit in a voltage-controlled oscillator. The output of the voltage-controlled oscillator is compared to a fixed frequency reference signal and a frequency/phase detector generates a signal indicative of any difference. The frequency/phase detector output is applied to the voltage-controlled oscillator to maintain the output frequency of the oscillator at the frequency of the reference signal. The output of the frequency/phase detector is also differentiated to develop a pulse when the frequency/phase detector output signal varies rapidly, indicating initial contact between the probe and the surface of a liquid held within a container.

Abstract: A reagent for use in immunoassays for rheumatoid factor (RF) is provided. The reagent contains heparin. Use of this reagent suppresses interference from the component Glq found in some test samples, and alleviates the need for a heat inactivation pretreatment of test samples to eliminate Clq interference.

Abstract: A method of operating a clinical analyzer wherein the analyzer includes a plurality of reaction locations divided into two groups. Predetermined operations are performed on the first and second groups during corresponding processing cycles. A process that is common to both cycles is performed simultaneously for reaction locations in the first and second groups during only one of the cycles. The other of the cycles can thus accommodate operations unique to particular tests that would not otherwise be available on the analyzer. The common process may be washing of adjacent reaction locations included in the first and second groups.

Abstract: A sample loading and unloading apparatus for an automated clinical instrument including a loading tray adapted to receive a plurality of sample carrying sectors. The apparatus further includes a sample carousel having a plurality of locations each adapted to receive sample sectors. The portion of the sample carousel nearest the loading tray defines a transfer position. The loading tray includes a transfer assembly for transferring a sector positioned at the transfer position from the sample carousel to the loading tray and simultaneously transferring a sector from the loading tray to the sample carousel. The transfer assembly includes a transfer spider which may be pneumatically raised to temporarily lift the sample sectors from the loading tray and the sample sector from the transfer position.

Abstract: A homogeneous liquid enzyme reagent for the quantitative determination of glucose comprises the enzymes hexokinase and glucose-6-phosphate dehydrogenase in a solution of glycerol (30% v/v) in water, and a stablizer system comprising a heavy metal ion chelating agent. Preferably the stabilizers also comprise an antioxidant and a microbic-control agent. The stabilizers are in sufficient amounts such that the enzyme reagent has a shelf life of at least about two years when stored at a temperature of from 2.degree. to 8.degree. C.

Abstract: A centrifuge hub-rotor drive is disclosed in which a rotor has an internal recess that fits over and interfaces with a hub. The hub has a skirt with a curved outer periphery that interfaces and contacts internal walls of the rotor which define a tapered section of the recess. The curved outer periphery of the skirt ideally meets the internal tapered walls of the rotor along a curved contact band. The outer periphery of the skirt is taken from a portion of a spheroid, regular, oblate or prolate.

Abstract: An efficiency extrapolation method is used in liquid scintillation counting for determining activity in an unknown sample. A dynamic and automatic determination of the range of the pulse height spectrum is used to permit a counting measurement in highly quenched samples, and with isotopes having low energy end points. A selected linear regression equation is extrapolated to provide the determination within a predetermined error established by a least squares condition.

Abstract: A sample handling system including a sample injection cell having an open chamber in turn comprising an upper portion for washing a sample handling probe and a lower portion adapted to reeive the probe for injection of a sample and fluid mixture into a flow analysis device. The cell enables the probe to be withdrawn from the cell and moved to other analysis modules for injection of sample therein. The cell includes a seal between the upper portion and lower portion of the chamber and the probe includes a mating seal near the tip of the probe. A plurality of conduits are formed into the cell for flowing sample and a fluid such as diluent through the cell to a flow analysis device and for filling the cell for washing the probe tip.

Abstract: An ion selective electrode flow cell includes a first fluid conduit and at least two ion sensing electrodes each having ion sensing surfaces disposed within the first fluid conduit. A second fluid conduit and an ion sensing electrode having an ion sensing tip is disposed within the second conduit. There is an electrically conducting bridge connecting the first and second fluid conduits. A conductive member is disposed within the first fluid conduit proximate the ion sensing surfaces of two ion sensing electrodes and the bridge. A third fluid conduit may intersect the first fluid conduit and can include grounding for grounding fluid flowing through the third fluid conduit. Capacitors between exit and entry ports of the first and second fluid conduits and ground reduce electrical noise within the flow cell.

Abstract: An analysis system including an ion selective electrode assembly, a sample container and a transport mechanism. The electrode assembly includes a reference electrode within a reference gel-filled well and ion selective electrodes disposed on an elongated portion of the electrode assembly. The sample container includes a body defining a plurality of reservoirs and a slot retaining an absorbant wiping and/or blotting material. The electrode assembly may be removably fixed relative to the transport mechanism. The transport mechanism includes a support table adapted to receive the sample container. The support table moves relative to the electrode assembly under the control of a cam to sequentially position the elongated portion of the electrode assembly within the reservoirs and the slot of the sample container.

Abstract: A system and method for performing a clinical assay, both including the use of a reaction capsule having a hydrophobic membrane which may be repeatedly wetted and rendered hydrophobic. A pressure differential across the membrane causes liquid flow therethrough to be initiated and the hydrophobic state is then achieved by flowing gas through the membrane. The system includes a turntable supporting a plurality of reaction capsules and eccentric means for agitating the turntable and capsules. The turntable is rotated to position the capsules at various processing stations, including sample introduction, reagent introduction, wash, substrate introduction and read stations. A single cylinder two-inlet valve may be used, one inlet connected to liquid and a second inlet connected to a gas source, to provide both liquid and gas flow through the membrane.

Abstract: A liquid scintillation solution consisting of a fluor and a select solvent is presented, said solvent having the generic formula ##STR1## where R.sub.1, R.sub.2, and R.sub.3 are either a methyl group or a hydrogen atom.

Abstract: A vial holder for a septum closed vial is disclosed which vial holder enables automated vial insertion to and withdrawal from puncturing hypodermics for the removal of contents or the communication of electrodes to liquids within the sealed vial. The vial--a commercial item of manufacture--includes a cylindrical glass body closed at the bottom and terminating upwardly at a narrowed neck to an opening. The opening accommodates both a septum and a septum retaining cap. A vial holder having an inside vial containing cavity with inside dimension complementary to the outside dimension of the vial is disclosed. This vial holder is formed from elastic material such as semirigid commercially available plastics and is vertically slotted from an open top at least partially to and towards the bottom of the holder. The vial holder is provided at the open top with inwardly extending fingers which register to the outside of the narrow neck of the septum sealed vial.

Abstract: An electrophoretic gel cooled cell including a gel supporting surface. The cell includes members for holding gels against the supporting surface such that gels of either of two dimensions may be used with the cell. A reservoir adapted to hold a cooling medium shares a common wall with the supporting surface to cool the gel retained by the members. The reservoir has a large opening which may be closed by a cover for easy insertion and removal of the cooling medium from the reservoir. A venting valve in the reservoir cover vents gas in the reservoir to atmosphere and closes when the cover is in an inverted position to prevent condensate leakage through the vent.

Abstract: Capillary zone electrophoresis systems are separated into two zones, one primarily for electroosmotic fow generation and the other dominated by electrophoretic effects, by the use of appropriately selected capillary materials for each region. Detection of the solute zones occurs in the electrophoretic region, minimizing or eliminating entirely the entry of the solutes into the electroosmotic region. The benefit acheived is avoidance or minimization of the adsorption of charged solutes by the capillary wall in electroosmotic flow.

Abstract: A novel agarose gel is provided for use in the high resolution electrophoretic (HRE) separation of serum proteins. The agarose gel employs a novel gel buffer which contains either hippurate, glycine, or a mixture thereof, in combination with barbital and Tris. The agarose gel of the present invention yields improved electrophoretic separation of the serum proteins in a sample whether the same gel buffer is also used as the running buffer or whether a standard barbital running buffer is used.