Abstract: Compounds that are modified polysaccharides having pendant aldehyde functionalities are disclosed. Each of the aldehyde functionalities is attached through a linker to a position corresponding to a hydrogen atom of a different hydroxyl group of unmodified polysaccharide. Also disclosed is a method for introducing an amine-reactive functionality into a dextran. The method comprises (a) reacting the dextran with an alkylating agent having a functionality that reacts with an hydroxyl group of the dextran thereby forming an alkylated dextran wherein the alkylating agent has an olefin group and (b) treating the alkylated dextran to convert the olefin group to an amine-reactive functionality. A polysaccharide can be conjugated to a biomolecule by carrying out the above method and reacting the amine-reactive functionality with an amine functionality on the biomolecule to produce polysaccharide conjugated to the biomolecule.

Abstract: The present invention provides methods and apparatus for mixing two or more liquids and detecting light emitted by the mixture. The method comprises forming a liquid droplet containing two or more liquids on a substantially planar surface in containerless containment on the surface and causing the droplet to deform in an essentially zero air flow environment thereby mixing the liquids and surrounding the planar surface with a reflective housing and photodetector. An apparatus of the invention comprises (a) a substantially planar support, (b) means for dispensing liquids onto the support to form a droplet, and (c) non-evaporative means for causing the droplet to deform without deforming the support thereby mixing the liquids and a two part reflective housing and photodetector which is moveable. The drop can be deformed by, for example, application of acoustic energy or a variable electrostatic field. The methods and apparatus have particular application to the determination of an analyte.

Abstract: A device is provided for both collecting and testing a fluid specimen. The device includes a specimen container having a collection chamber, an isolation chamber and a test chamber. The collection chamber is in fluid communication with the isolation chamber and sealed from the test chamber. The isolation chamber is also sealed from the test chamber. The fluid specimen is collected in the collection chamber and an aliquot is isolated in the isolation chamber. A fluid releasing element is provided to release fluid from the isolation chamber and establish a flow path to the test chamber while sealing the isolation chamber from the collection chamber. In accordance with another aspect of the present invention, the specimen container may include a tamper evident lid which provides an identification of whether or not the container has been opened which may indicate that the contents of the container have been compromised.

Abstract: The invention is directed to the preparation of magnetic and non-magnetic particles coated with a polyaldehyde dextran material and a process for making the same. The polyaldehyde dextran coated particles of the invention are suitable for use in immunological assays and exhibit a reduced matrix effect in such assays when compared to convention particles without a polyaldehyde dextran coating.

Abstract: Novel activated peptides and conjugates thereof, useful in diagnostic assays and therapeutics, and processes for the preparation thereof are disclosed.

Abstract: A chromogenic assay for determination of blood coagulation Factor VIII:Ca, using an indicator of Factor Xa simultaneously as a measure of Factor VIII:Ca concentration and as an inhibitor of Factor Xa. This technique can be applied to measure the concentration of an activating enzyme using the rate of conversion of the indicator molecule of the product of that enzyme as an indirect indicator of enzyme concentration.

Abstract: In an assay for determination of beta-lactam antibiotic resistance in a target bacterial strain, the strain is grown in the presence of both a beta-lactamese inducing antibiotic and a beta-lactam indicator antibiotic [which kills or inhibits the growth of bacteria] unable to hydrolyze beta-lactam antibiotics. Growth, indicative of drug resistance in the target strain, is monitored by detecting a fluorophor released by the enzymatic cleavage of a metabolizable fluorogenic compound.

Abstract: The present invention relates to methods for immunoassay of analytes employing mutant glucose-6-phosphate dehydrogenase (G6PDH) enzymes as labels. In particular, the invention relates to the use of conjugates of an analyte or analyte analog and a mutant NAD.sup.+ dependent G6PDH differing from any precursor G6PDH by the deletion, substitution, or insertion, or any combination thereof of at least one amino acid per subunit. The invention also involves the construction of several mutations in precursor glucose-6-phosphate dehydrogenase (G6PDH) enzymes. Typically, the mutations involve deletion or substitution of one or more lysine residues, or introduction of one or more cysteine residues by insertion of cysteine to precursor G6PDH or substitution of precursor G6PDH amino acids residues with cysteine.

Abstract: Avidin-binding azo reagents which alter the spectrophotometric properties of avidin and the use of such reagents in homogeneous assays are described.

Abstract: A method for extending the uselife of a chloride ion selective membrane of an ISE sensor by providing a two-layer sensor structure wherein an quaternized ion-selective polymeric layer is positioned between a sample to be analyzed and a conventional polymeric ISE membrane containing an ion-exchange agent. Also provided are polymer compositions comprised methyl methacrylate/choloromethyl styrene copolymer and mixtures thereof that have been reacted with tertiary amines.

Abstract: The present invention provides novel cyclosporine C (CsC) derivatives having improved protein conjugatibility and hydrolytic stability. The present invention further provides a CsC derivative conjugated to a carrier, e.g., a solid support. Preferably, the solid support is a latex or magnetic particle.

Abstract: Stabilized particle reagents suitable for use in turbidimetric immunoassays are disclosed. The stabilized particle reagents contain functionalized polymer particles in which the surface of the particle has been modified with a molecular surface modifier having the structure:R(OCH.sub.2 CH.sub.2).sub.n NH.sub.2in which: R is --H, --CH.sub.3 or --CH.sub.2 CH.sub.3, and n is an integer between 2 and 10, inclusive. The stabilized particle reagents are resistant to premature or spontaneous aggregation during preparation or storage.

Abstract: The present invention provides a method for indicating von Willebrand factor deficiency in a blood sample or platelet-rich plasma sample which exhibits abnormal platelet function comprising (a) adding a von Willebrand factor preparation to the sample, and (b) testing the sample for platelet function. In this method, the von Willebrand factor preparation restores normal platelet function and indicates that the sample initially lacked the von Willebrand factor. The von Willebrand factor preparation comprises purified von Willebrand factor. The invention also discloses a method which further comprises separating the blood sample into a plasma layer and cellular component layer and removing the plasma layer, prior to the step of adding a von Willebrand factor preparation to the sample. In this embodiment the von Willebrand factor preparation comprises platelet-poor plasma containing a normal level of von Willebrand factor.

Abstract: This invention pertains to fluorophoric compositions of a 7-amino-coumarin derivative and methods of their use for enhancing visualization of various constituents of ion selective electrodes.

Abstract: A method to dampen vibrations of a centrifuge by restraining vertical movement of a disk rotatably attached to the centrifuge's drive shaft. Damping bearings contact with the disk to restrain movement. Means responsive to the radial displacement of the disk activate the damping bearings beyond a predetermined displacement.

Abstract: A method for determining the presence of an analyte which is a specific binding pair member in a sample suspected of containing the analyte is described. The method involves: bringing together in an aqueous medium, the sample, an enzyme bound to a first specific binding pair member and an inhibitor for the enzyme bound to a second specific binding pair member wherein each specific binding pair member is capable of binding to the analyte or to a specific binding pair member complementary to the analyte; analyzing the medium for the activity of said enzyme; and relating the activity to the amount of analyte present in the medium. Compositions of matter and kits are also described.

Abstract: The present invention relates to a universal test systems and methods of use thereof for identifying a microorganism among at least two groups of widely divergent microorganisms. The universal test system comprises a predetermined combination of non-redundant biochemical tests comprising a substrate for at least one enzyme wherein the substrate, if acted on by the enzyme results in formation of a detectable product. Detectable products from the combination of biochemical tests are then used to identify the microorganism.

Abstract: A luminescent specific binding assay method is used for detecting an analyte in whole blood. The assay is a heterogeneous sandwich or competitive assay in which a first binding reagent is labeled with a luminescent photoprotein and an immobilized second binding reagent serves as a capture reagent. The luminescent photoprotein, upon activation, emits light which may be detected by a luminescence detector. The assay is rapid, sensitive and may be performed on small sample volumes.

Abstract: This invention pertains to a PT Assay Calibrator and a method of preparing a PT Assay Calibrator including a coagulation factor such as recombinant FVII or recombinant FVIIa that will allow preparation of PT calibration curves with values about 100% and which will give results analogous to those obtained using fresh normal plasma.

Abstract: A method is provided for enhancing the stability and increasing the activity of polymer particle reagents by incubating a polymer particle which has been covalently bound to a compound of biological interest, such as a drug, with a modifying agent that will place a negative charge on the surface of the polymer particle and reduce residual functional groups. The modifying agent is preferably an anionic nucleophile selected from the group consisting of .beta.- mercaptoacetic acid and the thiosulfates.