Abstract: A stable reagent and kinetic assay for .alpha.-amylase is provided. The reagent comprises a substrate for the .alpha.-amylase and various enzymes and cofactors necessary to produce NADH as the end-product of a series of four reactions. The substrate, enzymes, and cofactors are provided in sufficient excess that the .alpha.-amylase from the test sample is the rate-limiting factor. The concentration of .alpha.-amylase in a test sample is determined by measuring the rate of increase in absorbance caused by the production of NADH. The use of the novel cofactor fructose-1,6-diphosphate has been found to impart improved stability to the reagent.

Abstract: A reagent cartridge for use in an automated clinical analyzer, the reagent cartridge including a plurality of storage compartments each including wall members. The reagent cartridge includes connecting members formed integrally with the storage compartments for holding the storage compartments in a fixed relationship with respect to each other and separating the wall members from each other to thus prevent reagent migration between adjacent reagent compartments. Each of the storage compartments includes an access opening and a neck formed about the opening, the neck including a collar that is spaced a predetermined distance from a bottom wall of the associated storage compartment, the predetermined distance adapted to accommodate an automatically controlled reagent transfer probe.

Abstract: A system of modular analyzers each adapted for independent operation and each possessing different operational characteristics adapted for particular applications. Such modular analyzers may be joined together with precise indexing means such that a single sample carousel may be accessed by fluid transfer probes from both of the analyzers to thus form a system which operates as a single analyzer of increased capacity and versatility.

Abstract: A liquid degassing system including a liquid reservoir having an inlet to receive a liquid to be degassed and an outlet through which degassed liquid may flow. A vacuum source is controllably connected through a valve to the reservoir to draw gas out of the liquid held within the reservoir. A valve in a liquid inlet conduit supplying the reservoir may interrupt flow to the reservoir while vacuum is applied thereto. A second valve in an outlet conduit connected to the reservoir may interrupt flow from the reservoir when vacuum is applied to the reservoir.

Abstract: A temperature control apparatus for controlling the temperature of a plurality of cuvettes consisting of an annular sealed chamber containing a refrigerant, means fixed to the sealed chamber for receiving the sample cuvettes, a heater in thermal contact with the sealed chamber, and a temperature sensor in thermal contact with the sealed chamber. The sealed chamber may include a plurality of thermally conductive posts fixed to the chamber, the spacing between adjacent ones of the posts being adapted to receive the sample cuvettes.

Abstract: A device for holding and moving miniature electronic components utilizing an elastomeric material which grasps the sides of such components is described.

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 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: 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: 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 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: Apparatus for controlling reaction temperatures in a chemical analyzer comprises a thermoelectric element operating in response to a temperature sensor, and control means capable of predicting a setpoint deviation for a future time period, and, when an overshoot is predicted, reducing a control signal for the element by an amount proportional to a current setpoint deviation. The apparatus includes at least one reaction cell and a buffer unit for thermally stabilizing a fluid that is fed, on demand, into the reaction cell, the cell and the buffer unit having separate thermoelectric elements and sensors. A microcomputer control system generates independent control signals for the elements.

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.

Abstract: A novel competitive assay for theophylline wherein caffeine-like (7-substituted) labeled conjugates are used to detect the presence and/or amount of theophylline present in a test sample. The use of such conjugates in a competitive assay for theophylline results in improved sensitivity of the assay method. Where the assay method is a nephelometric or turbidimetric inhibition immunoassay procedure, the assay was found to be less temperature dependent than prior art immunoassays.