Abstract: The invention concerns a reagent system for the so-called on-board control of analytical elements, in particular test strips, containing an organic N-oxide or a nitroso compound. The invention also concerns analytical elements containing a reagent system for a detection reaction and a reagent system for an on-board control. Furthermore, the invention concerns a method for checking analytical elements in which a reagent system for an on-board control is examined optically or electrochemically with the aid of a measuring instrument for changes which could indicate a stress of the analytical element.

Abstract: The invention concerns a test device for analysing especially a biological sample liquid comprising a composite body (10) consisting of a plurality of layers of flat material (12, 18, 30) and a sample channel (20) located in the composite body (10) for transporting the sample liquid from an application site (22) to a measuring site (24). According to the invention it is proposed that the composite body (10) has a plurality of transport layers (18) arranged in a stack-like manner between support layers (12) for holding in each case a sample channel (20).

Abstract: The invention concerns an electrochemical sensor based on dry chemistry for determining blood coagulation or individual coagulation factors which has at least two electrodes on an inert support as well as a dry reagent, characterized in that the reagent contains a protease substrate which is composed of a peptide residue that can be cleaved off by a thrombin and is bound to a phenylenediamine residue via an amide bond at its carboxyl end and

Abstract: The invention concerns a method for the simultaneous colorimetric and electrochemical measurement of an analyte using an oxidizing enzyme and a chromogen A that accepts electrons from the enzyme which is characterized in that the chromogen A after reduction to A' reacts by coupling to a substance BX to form a colored substance A'B the concentratin of which is measured colorimetrically as a measure for the presence or amount of the analyte and in that an electrochemically measurable group X.sup.- is cleaved off during the coupling reaction the concentration of which is measured electrochemically as a measure for the amount of the analyte.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.

Abstract: The invention concerns a method for the colorimetric determination of an analyte by means of enzymatic oxidation with a PQQ-dependent dehydrogenase in the presence of an electron acceptor from the group of the electron-rich aromatic nitroso compounds by enzymatic reduction of the nitroso compound to an imino compound and detection of the imino compound by color formation. In addition the invention concerns a corresponding agent containing a PQQ-dependent dehydrogenase, an electon-rich aromatic nitroso compound as well as, if desired, a detection reagent for imino compounds. The invention in addition concerns novel nitrosoamino compounds which form colored quinone diimines on reduction as well as their use for the colorimetric enzymatic determination of an analyte.

Abstract: Test strip analysis system includes an analysis apparatus with a test strip holding device (3) and matching test strips. The test strip holding device (3) serves to position the test strip (4) in a defined position relative to a measuring unit (11). It includes a test strip seating device (20) and a guide for the test strip. Exact positioning with simple handling and without sophisticated mechanical elements is achieved by the fact that at least one part of the test strip seating device (20), in the area in which, in the measuring position, the front section (12) of the test strip is located, is formed as a support (24) which is offset in height relative to the middle plane (22) of the test field area (13). The test strip holding device (3) includes a pressure element (33) which, in the measuring position presses between the support (24) and the test field area (13) of the test strip (4) against the side (34) opposite the seating device ( 20) of the latter.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.