Root > Applications > Protein Production & Assays > Assays > The Strep-tag assay system

Applications for the Strep-tag® assay system

  • Antibody or serum screening (see applications)
  • Diagnostic assays
  • Expression cloning
  • Protein interaction studies
  • Screening of engineered enzymes
  • Drug screening 

The Strep-tag® assay system uses 8-well strips coated with either

  • Strep-Tactin®XT or 
  • Strep-Tactin®

allowing Strep-tag®II or Twin-Strep-tag® fusion proteins to be selectively captured from complex mixtures of molecules. The biomolecules are presented to interacting partners in a uniform manner which results in reliable and reproducible assay formats.



A comparison of immobilisation efficiency of Strep-Tactin®XT and Strep-Tactin® for Strep-tag®II and Twin-Strep-tag® fusion proteins can be found here.

Develop your own Assay!

Due to the high binding affinity of Strep-Tactin®XT with Twin-Strep-tag® in the low pM range, it is highly suitable for assays like SPR (surface plasmon resonance).

Request unconjugated Strep-Tactin®XT using this form:

Strep-Tactin®XT request