Abstract: The invention is a stable reagent used in assay systems that form a colored ferric ion complex, such as Prussian Blue. Such reagents are useful for the detection or measurement of an analyte from a fluid sample. Surprisingly, it has been found that the inclusion of certain ferric ion chelating agents, such as 3-sulfobenzoic acid, will inhibit formation of the blank reaction in the reagent.

Abstract: The operative site of an assay device is dosed with a controlled volume of a liquid specimen by a holding device which holds the controlled volume of specimen in contact with the operative site, although the holding device remains out of contact with the operative site. A sink device is in contact with the margin of the holding device and moves excess specimen away from the holding device. In one embodiment the device makes possible a non-wipe teststrip architecture. The device can be used in the detection of analytes including glucose or cholesterol in blood or urine and can be interrogated visually, optically or electrically, depending on the reagent used at the operative site.

Abstract: An immunoassay method and reagent system for determining nonenzymatically glucosylated proteins and protein fragments in a biological fluid based on the specific binding of such proteins and fragments with anti(Amadori-rearranged glucose), e.g., antibodies which selectively recognize the rearranged deoxyfructose form of glucose resulting when proteins are nonenzymatically glucosylated. The antibodies are raised against an immunogen comprising an immunogenic carrier material bearing 1-deoxy-1-fructosyl residues or conformers of such residues. Measurement of nonenzymatically glucosylated proteins and fragments thereof provides a useful index of blood glucose levels.