Abaxis, Inc.

Steven N Buhl

Bhaskar Bhayani

Thuy N Tang

Chi-Sou Yu

Carol T Schembri

Tammy L Burd

Anne R Kopf-Sill

Robert E Nagle

Gary L Smith

Vladimir E Ostoich

Glenda L Choate

Boris Braynin

Daniel M Bernstein

Lloyd A Schick

Wayne A Britt

Jenq C Chang

Branko Huc

Christian Skieller

Terri Bogart

Bikash K Chatterjee

Anthony Alvarado

Swee Wong

The present invention provides dried chemical compositions comprising dried beads. Typically, the beads comprise reagents suitable for analysis of biological samples, in particular analysis of blood samples in centrifugal analyzers.

Dried chemical compositions

The present invention provides lyophilized reagent spheres comprising reagents suitable for analysis of biological samples, in particular analysis of blood samples in centrifugal analyzers. Also provided are diluents which are conveniently used in such analyzers.

Reagent compositions for analytical testing

The present invention provides various methods for detecting errors in a blood analysis system. The system includes a blood analyzer and a molded plastic rotor with a series of chambers and capillary channels through which blood is processed and distributed to cuvettes which contain lyophilized reagents. The rotor is placed in the analyzer which spins the rotor, and an optical system reads the cuvettes as light is flashed through the cuvettes. The invention provides checks for: confirming the presence of a reagent in the cuvettes before a sample is applied to the cuvettes; determining whether a fluid sample has been properly distributed to the cuvettes of the rotor; determining whether an adequate amount of fluid sample was applied to the analytical rotor; determining whether a fluid sample has been properly distributed to a cuvette of an analytical rotor; determining whether a reaction chemistry in a cuvette has reached an end point; checking the noise level and non-linearity of a reaction rate in a cuvette; determining whether an adequate amount of diluent was delivered to the cuvettes of an analytical rotor; determining dilution systematic failure when measuring different reaction chemistries in the cuvettes of the rotor; determining whether a blood sample in a cuvette is hemolyzed, lipemic, or icteric; determining the degradation of a reagent in a cuvette; determining proper light source and light detector operation; and determining proper motor function and cuvette mark detection.

Error checking in blood analyzer

The present invention provides methods and devices for freezing drops of liquid reagent solution in a cryogenic liquid. In one embodiment, the apparatus of the present invention comprises means for dispensing uniform, precisely measured drops of a liquid reagent and a rotatable carousel positioned below the dispensing means. The upper surface of the carousel has a plurality of trays each containing a cryogenic liquid, typically liquid nitrogen, for receiving the drops of liquid reagent. An alternative embodiment of the present invention comprises a tank comprising a cryogenic liquid for receiving the drops of liquid reagent. The tank has a heat source for slightly heating a portion of the cryogenic liquid such that a convection current in the cryogenic liquid is created. The convection currents in the cryogenic liquid provide mild agitation of the liquid and prevent aggregation of the frozen drops.

Cryogenic apparatus

An analytical rotor for separating plasma whole blood comprises a rotor body having a sample application port in an upper surface thereof. Blood introduced to the sample application port is metered into a metering chamber by capillary flow while the rotor remains stationary. Excess blood passes into an overflow chamber by capillary flow, either simultaneously with the metered flow or after opening of a vent in the overflow chamber. Subsequent rotation of the rotor causes metered blood in the metering chamber to flow into a receiving chamber, typically a plasma separation chamber.

Sample metering port for analytical rotor having overflow chamber

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Cupertino, CA, United States of America

Steven N Buhl