MagStrep® Strep-Tactin® beads

MagStrep® Strep-Tactin® beads are an ideal tool for the isolation of BioID targets and strep-tagged proteins or identification of complexes via pull-downs in batch format and high-throughput screenings. For cell isolation we offer magnetic microbeads with a smaller diameter. We also recommend our MagStrep® Strep-Tactin®XT beads if you need increased binding affinity in the pM range for protein purification. The advantage of Strep-Tactin® over native streptavidin is that it binds to BioID targets in a reversible manner. The binding can be released by adding biotin in excess. As streptavidin binds irreversibly to BioID targets, they can only be eluted by boiling. Strep-Tactin® however still binds biotin and therefore also BioID targets, but with a lower binding affinity compared to streptavidin, making the binding reversible. Separation of beads is easy with a magnetic separator. Elution of strep-tagged or biotinylated proteins can be done by using buffer BXT containing biotin for purification under physiological conditions or under denaturing conditions by boiling in SDS gel loading buffer for elution.