Learn how to use this product Strep-Tactin® Sepharose® columns are intended for the purification of Strep-tag®II or Twin-Strep-tag® fusion proteins in gravity flow. The low percentage of agarose (4%) allows the purification of large proteins. For proteins with multiple tags, such as multimers, that cannot be eluted from Strep-Tactin®XT resins due to the increased affinity, Strep-Tactin® Sepharose® columns are a lower affinity alternative. Biotin will bind irreversibly to Strep-Tactin®, and we recommend masking free biotin with BioLock (IB 2-0205-050) before sample application. Furthermore, the Strep-tag®II binding capacity is 3 mg/ml. The use of the WET FRED application aid is recommended to reduce the waiting period during the sample and buffer application. For columns with a custom resin bed volume, use Strep-Tactin® Sepharose® 50% suspension (IB 2-1201-002). Please check our other resins' specifications if you have different purification requirements.