Abstract: The present invention concerns muteins of avidin and streptavidin with a reduced binding affinity for biotin as well as their use as interference elimination reagents in methods for the determination of an analyte e.g. in diagnostic tests such as for example immunoassays and nucleic acid hybridization assays. In addition the invention concerns the use of muteins of avidin and streptavidin as systems capable of regeneration for binding biotin e.g. for the analysis of biotinylated molecules, for examining receptor ligand interactions as well as for the affinity purification of biotinylated molecules.

Abstract: The present invention concerns muteins of avidin and streptavidin with a reduced binding affinity for biotin as well as their use as interference elimination reagents in methods for the determination of an analyte e.g. in diagnostic tests such as for example immunoassays and nucleic acid hybridization assays. In addition the invention concerns the use of muteins of avidin and streptavidin as systems capable of regeneration for binding biotin e.g. for the analysis of biotinylated molecules, for examining receptor ligand interactions as well as for the affinity purification of biotinylated molecules.

Abstract: The present invention concerns muteins of avidin and streptavidin with a reduced binding affinity for biotin as well as their use as interference elimination reagents in methods for the determination of an analyte e.g. in diagnostic tests such as for example immunoassays and nucleic acid hybridization assays. In addition the invention concerns the use of muteins of avidin and streptavidin as systems capable of regeneration for binding biotin e.g. for the analysis of biotinylated molecules, for examining receptor ligand interactions as well as for the affinity purification of biotinylated molecules.

Abstract: The invention concerns a homogeneous immunoassay based on agglutination using an Fab′-biotin material and agglutinatable particles which carry streptavidin or avidin. The invention also concerns the Fab′-biotin which is bound or linked via linkage groups to a label compound which can electrochemiluminescence and the particles having avidin or streptavidin on their surface are magnetic.

Abstract: The application describes homogeneous assays for determining ligands. A sample is contacted with a labeled substance P.sub.2 and receptor R. The receptor R consists of one molecule of P.sub.1, which monovalently and specifically binds to P.sub.2, and one molecule for R.sub.1, which binds to the ligand of interest. Complexes of P.sub.1, P.sub.2, R.sub.1 and ligand form, and are determined. R.sub.1 must be a nucleic acid molecule.

Abstract: Method for the immunological determination of a ligand in which the ligand to be determined is reacted witha) at least 2 molecules of a specifically bindable substance P2 of which at least one of these molecules carries a label andb) a receptor R which consists of a binding partner P1 which is capable of monovalent binding to P2 and a binding site R.sub.1 for the ligand to be determined and then the label is determined,as well as a reagent for the immunological determination of a ligand which contains a specifically bindable substance P2 which is present at least partially in labelled form and a receptor R which consists of a binding partner P1 which is capable of monovalent binding to P2 and a binding site R.sub.1 for the ligand to be determined.

Abstract: In order to determine an analyte by a heterogeneous immunological test using a first partner of a binding pair which is immobilized on a solid phase in which a sample solution containing the analyte is incubated in the presence of the solid phase with either(1) a first conjugate consisting of (a) the second partner of the above-mentioned binding pair and (b) a first substance capable of specific immunological binding to the analyte or(2) a first conjugate consisting of (a) the second partner of the above-mentioned binding pair and (b) a first substance capable of specific immunological binding to the analyte as well as with a second labelled substance capable of specific immunological binding to the analyte,afterwards the phases are separated, in case (1) the liquid phase is replaced by a further solution containing a second labelled substance capable of binding specifically to the analyte and it is again incubated and subsequently separated, and in both cases the label on the solid phase or in the liquid pha

Abstract: A specific binding pair is bound to an insoluble carrier for use in determining an analyte such as in an immunoassay. The carrier is coated with a first polymer containing a protein polymer having a molecular weight of at least about 20,000 and molecules of a first member of a specific binding pair. A second polymer containing a second member of the specific binding pair is bound to the first member on the carrier by binding of the first and second members of the specific binding pair. The first polymer is preferably more hydrophobic than the second polymer. The protein polymer can be prepared by cross-linking hydrophobic protein molecules of 10,000 to 700,000 molecular weight with a bifunctional or polyfunctional compound to obtain a protein polymer of 200,000 to 20,000,000 molecular weight. The second polymer can be the second member of the specific binding pair or the second member cross-linked with a linker or the second member cross-linked to a hydrophobic protein.

Abstract: The present invention provides a process for the detection of analytes in body fluids containing free biotin by immunoassay with the use of biotin conjugates for the labelling, immobilization or complexing of immunological reagents, wherein the biotin present in free form is removed from the immunological reaction by incubating the sample solution with polymer particles consisting of a core and a covering which, as core, contain a polymer which has a plurality of binding sites for biotin and, as covering, at least one layer of protein, peptide, carbohydrate or co-polymer of carbohydrate and amino acids, the layer thickness of the covering being so adjusted that the coating is permeable for the free biotin but not for the biotin conjugate.