Ready-to-use Strep-TactinXT coated microplate (12 x 8-well strips) for ligand binding assays, immuno assays, enzyme assays, or diagnostic assays under high-throughput conditions. Due to the high specificity and affinity (nM-pM) of the streptavidin variant Strep-Tactin XT, Strep-tagII or Twin-Strep-tag fusion proteins can be selectively and stably captured even from complex mixtures. Biomolecules of interest are presented to interacting partners in a uniform manner resulting in reliable and reproducible assays.The solid-phase, multi-well format is compatible with standard multichannel pipettes and automated plate readers. Twin-Strep-tag fusion protein binding capacity determined with bacterial alkaline phosphatase (97 kDa) is 4 pmol for 200 µl incubation volume.