Inactive mutant recombinants cenral of streptavidin.

The present invention REFERS TO muteins of avidin and streptavidin lower affinity biotin binding and their use as reagents for INTERFERENCE ELIMINATION OF PROCEDURES determination of an analyte, EG. DIAGNOSTIC TESTS AS immunoassays and hybridization assays Nucleic Acid. The invention further relates to the use of avidin and streptavidin muteins AS SYSTEMS FOR UNION regenerable Biotin, eg MOLECULES FOR ANALYSIS biotinylated, RESEARCH AND INTERACTION receptor-ligand affinity purification of biotinylated MOLECULES.