Eastman-kodak Company

Johnson & Johnson Clinical Diagnostics, Inc.

Linda A Mauck

John C Mauck

Wayne A Bowman

Richard C Sutton

Susan J Danielson

John F Bishop

Thomas R Kissel

Margaret J Smith-Lewis

Gary E Norton

Alan E Friedman

Robert Edwin Emmons

Royden N Rand

Angelo P Andrese

TaiWing Wu

A dry immunoassay analytical element, for assaying a ligand is disclosed. The element comprises, in the following order, (a) a layer containing a labeled ligand, (b) a bead spreading layer, c) a cross-linked hydrophilic polymer layer and d) a support; wherein (i) a fixed concentration of an immobilized receptor for the labeled ligand is located in a zone at the interface of layers (b) and (c); and (ii) the receptors are immobilized by being covalently bonded to polymeric beads that are smaller than the beads in layer (c).

Immunoassay elements having a receptor zone

An immunoassay element comprising at least one layer containing a leuco dye coating composition comprising:

Immunoassay elements having stable leuco dye coatings

A dry analytical element can be used to sensitively and rapidly detect a wide variety of specific binding ligands in either a competitive binding or sandwich assay format. The assays are carried out using a peroxidase-labeled immunoreactant. The peroxidase label is stabilized with a 4-hydroxy or 4-alkoxyarylacetamide which is located in one or more zones of the element. Not only is the label stabilized with the stabilizer, but the assay is more sensitive.

Analytical element and method for the determination of a specific

Dry transparent analytical elements can be used to determine analytes which have been separated by electrically induced migration through a solid medium, e.g. by electrophoresis, or which are intracellular enzymes. The dry transparent element is placed on a plate containing the analytes, and kept there until the analytes have reacted to produce a non-diffusible detectable species solely in the element. The element is removed and the detectable species is evaluated therein. The elements contain a water-insoluble binder material having an interactive composition dispersed therein which reacts with analyte to produce the non-diffusible species. The same electrophoretic plate can be used to successively determine the same or a plurality of analytes since it is not altered or destroyed by contact with the dry element.

Use of dry analytical elements to determine analytes

An analytical element can be used for the determination of either creatinine or creatine or both. The element contains creatinine amidohydrolase, creatine amidinohydrolase and sarcosine oxidase, and a leuco dye which is capable of providing a detectable dye in the presence of hydrogen peroxide and a peroxidative substance. The creatine amidinohydrolase is present in a manner such that it is substantially inert to the leuco dye. The creatinine amidohydrolase is present in a rate limiting amount. By measuring the amount of dye formation at particular times during the assay, either or both of the analytes can be determined with the same element.

Analytical element and method for the determination of creatinine or

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Rochester, NY, United States of America

Linda A Mauck