Strep-TactinXT BLI Coupling Kit is intended for site-directed, reversible capture of Twin-Strep-tag fusion proteins for biomolecular interaction analysis using Bio-Layer Interferometry (BLI). It provides Strep-TactinXT, Immobilization Buffer, Ethanolamine, EDC, and s-NHS sufficient for coating of 96 biosensors (1 tray). The pM affinity of Strep-TactinXT for Twin-Strep-tag fusion proteins allows specific capture even from complex samples, e.g., culture supernatants. Coated biosensors can be easily regenerated by application of the provided Regeneration Buffer without loss of the Strep-TactinXT coating which enables multiple re-uses.