Syva Company

Sclavo, Inc.

Other

Gerald L Rowley

Edwin F Ullman

Ian Gibbons

Naomi Kameda

Danton Leung

Robert F Zuk

Prithipal Singh

Phuc H Nguyen

Henry K Tom

Larry R Hillis

Prithiphal Singh

Ronald Robert C

A method to convert the hydroxyl groups of solubilized dextran to the tresylate forms which can be displaced by a nucleophile is disclosed. The method of the invention requires the reaction of dextran with the tresylating reagent in the presence of dry DMSO. The resulting tresylate can be converted to labeled dextrans which have direct linkages of a nucleophilic label to the carbons of the dextran backbone.

Method to derivatize dextran

Methods and materials for preparing specific binding reagents with a multiplicity of relatively noninterfering label moieties are described. By spacing the labels at the surface of a specific reagent with bulking agent, increased sensitivity can be achieved without interference between individual labeling entities.

Labeling design for a binding assay reagent

A method for conducting assays for an analyte, usually in a biological sample, utilizes reagents which contain biological ligands linked to fluorescein or a derivative of fluorescein through a linkage to the fluorescein nucleus selected from acetamido and thioacetamido. In these reagents, the fluorescence efficiency is improved over that obtained in the commonly used FITC-labeled reagents.

Fluorescein-conjugated proteins with enhanced fluorescence

An improvement in an assay method which relies on the detection of a labeled, solubilized specific binding complex is achieved by linking the label to a component of the complex through a bond cleavable under conditions compatible with the assay and with the complex in solution.

Cleavable labels for use in binding assays

A method for determining a member of a specific binding pair-ligand and receptor (antiligand). Reagents employed include a first modified member which provides an electrical field due to the presence of a plurality of ionic charges and a second modified member labeled with a component of a signal producing system, which system may have one or more components. The average proximity in the assay medium of the first and second modified members is related to the amount of analyte, where the observed signal from the signal producing system is related to the effect of the electrical field on the signal producing system. Also, compositions are provided, as well as reagents, in predetermined ratios for optimizing the signal response to variations in analyte concentration.

Charge effects in enzyme immunoassays

Method and apparatus are provided for performing immunoassays employing a device comprising a relatively small test zone referred to as an immunosorbing zone, and a relatively large liquid absorbing zone in liquid receiving relationship with said immunosorbing zone. The immunosorbing zone includes a member of an immunological pair ('mip')--ligand and antiligand--bound to a support. A signal producing system is employed in conjunction with said device having as one component a signal label bound to a mip. The signal producing system provides for production of a detectible signal in the immunosorbing zone in relation to the amount of analyte in a sample.

Concentrating zone method in heterogeneous immunoassays

Methods and compositions are provided for conjugating a wide variety of compounds, particularly polyfunctional compounds, having a mercapto group, either naturally present or synthetically introduced, to a polyamino compound, particularly a polypeptide (including proteins). The method employs a haloalkyl-carbonyl compound, which is conjugated to one or more of the amino groups under mild acylating conditions. This is followed by combining the acylated polyamino compound with a mercapto containing compound, whereby the halogen is displaced by the sulfur of the mercapto group to form a stable thioether linkage. The resulting conjugates, depending on the compounds involved, can find uses in immunoassays, as hapten-antigen conjugates for the production of antibodies, and as ligand analog enzyme conjugates for use as reagents in controlling the distribution of substitution of a mercapto compound to a polyamino compound.

Enzyme-aminoglycoside conjugates

Method and compositions are provided for performing homogeneous immunoassays. The method involves having a signal producing system, which provides a detectable signal, which system includes a macromolecular member. The determination of the analyte, which is a member of a specific binding pair consisting of a ligand and its homologous receptor, is performed by creating an extensive matrix in the assay medium by having in the assay medium in addition to the analyte, ligand labeled with one of the members of the signal producing system, antiligand either present as the analyte or added, a polyvalent receptor for antiligand, the macromolecular member of the signal producing system, and any additional members of the signal producing system. The labeled ligand, antiligand, and polyvalent receptor for the antiligand create a matrix which modulates, e.g. inhibits, the approach of the macromolecular member of the signal producing system to the labeled ligand. The extent and degree of formation of the matrix is dependent upon the concentration of the analyte in the medium. By comparing the signal from an assay medium having an unknown amount of analyte, with a signal obtained from an assay medium having a known amount of analyte, the amount of analyte in the unknown sample may be determined qualitatively or quantitatively. Kits are provided having predetermined amounts of the various reagents to allow for enhanced sensitivity of the method.

Double antibody for enhanced sensitivity in immunoassay

Methods and compositions are provided for conjugating a wide variety of compounds, particularly polyfunctional compounds, having a mercapto group, either naturally present or synthetically introduced, to a polyamino compound, particularly a polypeptide (including proteins). The method employs a haloalkylcarbonyl compound, which is conjugated to one or more of the amino groups under mild acylating conditions. This is followed by combining the acylated polyamino compound with a mercapto containing compound, whereby the halogen is displaced by the sulfur of the mercapto group to form a stable thioether linkage. The resulting conjugates, depending on the compounds involved, can find uses in immunoassays, as hapten-antigen conjugates for the production of antibodies, and as ligand analog enzyme conjugates for use as reagents in controlling the distribution of substitution of a mercapto compound to a polyamino compound.

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San Jose, CA, United States of America

Gerald L Rowley