Biotin
Biotin, also known as vitamin B7 or vitamin H, binds to streptavidin, Strep-Tactin®, and Strep-Tactin®XT with varying affinities. It can be used to prepare Strep-Tactin®XT elution buffer (Buffer BXT), where it efficiently displaces bound Strep-tag®II or Twin-Strep-tag® proteins from the resin, enabling effective elution.