Strep-tag® vs His-tag
Benefits of Strep-tag® vs His-tag purification
Comprehensive comparison of Strep-tag® and His-tag protein purification systems
Protein purification protocols
Strep-tag® performs better than His-tag in purification of mammalian-expressed proteins
In combination with high density mammalian protein expression, the His-tag system can lead to poor purification results, if conditions are not optimized. In order to achieve pure proteins for downstream applications from the coupling of the His-tag system and high density mammalian systems, further adjustments like dialysis of the supernatant, lower media:resin ratios or the use of strip-resistant nickel resins become necessary. Such adaptions require additional optimization time and effort, however, these challenges can be avoided by using the Strep-tag® system.
The following whitepaper shows the advantages of the Strep-tag® technology in comparison to the His-tag system as well as the excellent connection of the Strep-tag® technology with two high density mammalian expression systems, the Expi293TM and the ExpiCHOTM expression systems.
Protein purification under denaturing conditions
The improved binding affinity of Strep-Tactin®XT to Twin-Strep-tag® enables high protein purities under both native and denaturing conditions. Simultaneously, successor Strep-Tactin®XT preserves all benefits of common Strep-Tactin®, e.g. physiological buffer conditions, mild elution and regeneration of the resin for re-use. Besides this outstanding performance the Strep-Tactin®XT:Twin-Strep-tag® system now offers the possibility to efficiently purify proteins under denaturing circumstances: After successful purification, Strep-Tactin®XT ensured purer protein than the NiNTA:His6-tag system for concentrations up to 6 M urea. Read more in the application note below.