Becton Dickinson and Company Limited

Strategic Diagnostics Inc.

Ensys Environmental Products, Inc.

James P Mapes

Glenn P Vonk

Thomas N Stewart

Randal A Hoke

Thomas H Schulte

Stewart R Jurgensen

Beverly M Fleming

Ali Naqui

Liane F Gossett

Catherine S Donahue

A chromatographic strip positive readout binding assay device and method suitable for quick, sensitive and reliable field testing for small molecules such as environmental contaminants, drugs of abuse, therapeutic drugs and hormones. The detectable label is not attached to either the analyte or to the analyte receptor. Low affinity binding pairs can be used in the positive readout binding assay.

Indirect label assay device for detecting small molecules and method of use thereof

Indirect label assay device for detecting small molecules and method of

A method for detecting urea in a liquid sample in which urease is adsorbed on a solid support such as a membrane and contacted with a solution suspected of containing urea, a pH-dependent reducing agent and a tetrazolium salt. When urea is present in the solution, the adsorbed urease converts it to ammonia, thus raising the pH and causing the pH-dependent reducing agent to reduce the tetrazolium salt to an insoluble colored formazan. The formazan precipitates as a detectable spot on the solid support, indicating the presence of urea in the liquid sample.

Solid phase assay for urea

A substrate composition for use in a solid phase enzyme assay for urease or in a solid phase enzyme immunoassay which includes urease as a label. The substrate composition includes a compound converted by urease to ammonia and a pH dependent reducing agent which reduces a tetrazolium salt when the pH of the medium has been raised by the ammonia produced. The tetrazolium salt may optionally be included in the substrate composition. Reduction of the tetrazolium salt produces a colored insoluble formazan which precipitates on the solid phase as an indication of the presence of urease.

Substrate composition for solid phase urease immunoassay

An assay for Chlamydia includes contacting Chlamydia organisms in a liquid with a solid support having an antispecies Fe antibody immobilized thereon and an anti-Chlamydia capture antibody. After binding of Chlamydia antigen to the capture antibody and binding of the capture antibody to the antispecies antibody on the support, a tracer including a label conjugated to a signal antibody is added. After binding of the signal antibody to the antigen, the presence of Chlamydia organisms in the liquid is detected by a signal associated with the label thereby bound to the support. The invention includes a kit of materials for performing an assay according to the method of the invention.

Layered sandwich assay method for chlamydia and materials therefor

Diagnosis of Lyme disease by immunoassay for anti-Borrelia burgdorferi antibodies in the serum of a patient includes adsorption of crossreactive antibodies in the serum with antigen of Acinetobacter calcoaceticus or Treponema phagedensis prior to binding of anti-Borrelia antibodies to Borrelia burgdorferi antigen absorbed onto a solid support. The preferred assay is a flow-through assay using a porous membrane as the support and a dye-loaded liposome conjugated to a goat antihuman antibody for detection. The invention includes a kit of materials for performing the assay.

Assay for lyme disease

A method for enzyme immunoassay of a ligand includes urease as a label. A bound fraction of ligand and antiligand conjugated to urease is formed on a solid support. The urease component of the bound fraction is contacted with a substrate composition for urease which includes a compound converted to ammonia by the urease, a tetrazolium salt and a pH dependent reducing agent which reduces the tetrazolium salt when the pH of the assay medium has been raised by the ammonia. The tetrazolium salt is reduced to a colored insoluble formazan which precipitates as a detectable spot on the support. The invention includes the substrate composition and a kit of materials for performing the assay.

Substrate composition and method for solid phase urease immunoassay

A method for assaying of Chlamydia includes adhering Chlamydia antigen to amidine modified latex particles, binding of adhered antigen to an anti-Chlamydia antibody conjugated to an enzyme, separating the particles from the liquid phase of the assay and detecting bound enzyme by color development when the separated particles are contacted with a substrate for the enzyme. The invention includes a kit of materials for preforming an assay in accordance with the method of the invention.

Chlamydia assay using amidine modified supports or particles

The invention relates to liposome compositions comprising liposomes in an aqueous buffer at a pH of 6.5-8.5 and including a polyol in an amount of from 0.6 to 1.5 g per 100 ml of buffer. Also, the invention further relates to liposome compositions comprising a liposome including a detectable marker wherein said liposome may be derivatized with a ligand and the use thereof in an assay for analyte of interest.

Storage and use of liposomes

A method for enzyme immunoassay includes contacting under binding conditions a liquid suspected of containing an analyte, an antianalyte affixed to a solid support and a tracer having an enzyme conjugated thereto. A bound fraction is separated from the liquid and incubated in a second liquid with a masked ligand. The masked ligand is converted by the enzyme on the bound fraction to give free lignad which binds to an antiligand. A signal system, such as a signal enzyme and substrate therefor, or a label-loaded vesicle and vesicle lysing agent, is added to generate a signal used to detect or measure the analyte in the liquid. The invention includes a kit of materials useful in performing the assay of the invention.

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Raleigh, NC, United States of America

James P Mapes