Abstract: Test carrier for the analytical determination of a constituent of a sample fluid by a specific binding reaction between two binding partners having biological affinity. A plurality of test layers is so disposed that they are wetted successively by the fluid and form a fluid transport path, in which one of the test layers is a fixing layer (18) which is a porous carrier matrix. The first of the two binding partners is fixed to the latter. The fluid containing the second binding partner flows through the fixing layer (18), at right angles to its surface, on the test carrier (10).A largely complete binding reaction in an extraordinarily short time is achieved during the flow through the preferably very thin fixing layer (18) by the fact that a microporous plastics layer with a pore size P of at least 0.

Abstract: On a carrier layer there are arranged several test layers which are at least partly in fluid contact with one another, enabling liquid exchange. On the carrier layer are arranged an application zone, a detection zone for the production of a detectable signal characteristic of the analytical determination, which contains at least one said test layer which is a reaction layer, and an absorption zone with a test layer which is an absorptive layer of an absorbent material, wherein the reaction layer and absorption zone are positioned next to each other. Between the application and the absorption zone is a capillary-active transport path on the carrier layer which connects the application zone and the absorption zone. The reaction layer is arranged parallel to the transport path between the application zone and the absorption zone in such a manner that it is in liquid contact with a liquid transported in the transport path.

Abstract: Compositions and methods for rapidly determining ascorbic acid in aqueous solutions, consisting of an absorbent carrier containing 2,18-phosphomolybdic acid, an aliphatic hydroxycarboxylic acid buffer to adjust the test to pH 2.5 to 5.0, and an alkali chlorate; process for the preparation of such tests.

Abstract: Microbiological test device having a nutrient card or cards and a covering layer thereover which is permeable to nutrients but impermeable to bacteria. The covering layer is made from an aqueous dispersion of a water insoluble resin and a pore former.