Protein Complex Purification and Protein:Protein Interaction Analysis

Twin-Strep-tag® – The high affinity tag

Based on its proprietary Strep-tag® technology IBA developed the Twin-Strep-tag® (tandem Strep-tag®) for a mild and rapid purification of intact protein complexes on immobilized Strep-Tactin®.

The Twin-Strep-tag® combines high specificity and mild conditions with higher affinity thereby enabling efficient purification directly from culture supernatants. Furthermore, it tolerates elevated detergent concentrations to reduce background.

The Twin-Strep-tag-former One-Strep tag

Twin-Strep-tag (former One-STrEP-tag):


Properties / Benefits

  • Twin-Strep-tag has a neutral amino acid composition
  • Purification of recombinant proteins to over 99 % purity in a single step
  • High affinity leads to good protein yields even in from cell culture supernatant
  • Very low tendency of Strep-Tactin® to bind other proteins non-specifically
  • Highly specific Twin-Strep-tag:Strep-Tactin® interaction
  • Specific competitive elution with minute amounts of (desthio-)biotin in the physiological wash buffer


For further information on Twin-Strep-tag applications see protein interaction section.

! The purification of Twin-Strep-tag fusion proteins is based on the same principle as for Strep-tag® II proteins. Please refer to Strep-tag® for more details !