Abstract: The invention concerns a method for detecting an analyte in a blood sample or a derived fraction thereof. In this method one uses the binding affinity between the analyte and its specific binding agent. Moreover, a reaction component containing a peroxidase label is added to the sample and specific binding agent to form a reaction mixture. The incubation of the reaction mixture, containing the analyte and its specific binding agent, with the peroxidase-labeled reaction component has to be carried out in the presence of a quaternary ammonium salt or ionic surfactant.

Abstract: Device for the carrying out of an immunochemical determination comprising at least one holder which is provided with an opening at the top and to the inside of which an immunochemically active substance has been applied. The device is closed at the top by a removable closure means and the holder contains at least a second immunochemically active substance which, in the absence of test medium, in the form in which the second immunochemically active substance is contained in the closed holder, during storage and transport under normal conditions exhibits no interaction with the inside of the holder and is inert with respect to the immunochemically active substance applied thereto. The holder contains a solid, more or less spherical, freeze-dried particle which contains the second immunochemically active substance.

Abstract: A method for the demonstration and determination of an antigen or antibody in a test fluid, and to a test kit for the application of this method. The determination of the antigen or antibody is performed by utilizing two antibodies raised against the same antigen, but in different animal species. One of the antibodies is labeled. In order to separate the labeled-bound fraction from the labeled-free fraction, an insolubilized antibody directed against the unlabeled antibody is employed. For antigen determination, the unlabeled antibody is the antibody produced from the second animal species; for antibody determination, the unlabeled antibody can be either the antibody to be detected or determined or the antibody produced from the second animal species.