Eastman-kodak Company

Allen L Thunberg

Glen M Dappen

James Albert Reczek

Susan J Danielson

Michael W Sundberg

Gary E Norton

Karl J Sanford

Paul H Frickey

Denise D LaRossa

Ferric ion chelates are useful in analytical compositions, elements and methods for the determination of reductants, or other analytes which can produce a reductant. The ferric ion chelate is reduced to ferrous ion, which coordinates with a suitable ferrous ion coordinating ligand to form a colored complex. In particular, these compositions and elments are useful for detecting nicotinamide adenine dinucleotide, reduced form (NADH) or nicotinamide adenine dinucleotide phosphate, reduced form (NADPH), or an analyte (e.g. an enzyme) which produces NADH or NADPH in biological fluids.

Analytical compositions, elements and methods utilizing reduction of

A heterogeneous, competitive binding immunoassay is conducted with a dry analytical element. The immunoassay is useful for determining a ligand (e.g. a therapeutic drug) and includes contacting a finite area of the element spreading layer with a sample of a liquid in the presence of a labeled ligand analog and an immobilized receptor. An immobilized ligand-receptor complex is formed within the finite area. Simultaneously, the uncomplexed ligand migrates horizontally away from the immobilized complex which remains in the center of the finite area. At least five seconds after the completion of the contacting, the amount of immobilized complex is measured in the center of the finite area.

Heterogeneous immunoassay utilizing horizontal separation in an

Disclosed herein is a dry analytical element and a method of using same for quantitatively detecting alkaline phosphatase in an aqueous liquid. The element comprises, in fluid contact, first and second reagent zones which can be self-supporting or carried on a support. The first reagent zone contains a substrate for alkaline phosphatase, e.g. p-nitrophenyl phosphate, and the second reagent zone contains a buffer which is an alkali metal or ammonium salt and has a pKa in the range of 9-11.5, e.g. an alkali metal salt of carbonic acid.

Analytical element and method for alkaline phosphatase assay

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Pittsford, NY, United States of America

Allen L Thunberg