Strep-tag® vs His-tag
Benefits of Strep-tag® vs His-tag purification
Strep-tag® and His-tag are both widely used tools for affinity purification via a peptide tag. But when it comes to purity and versatility in applications, some differences between both systems are obvious. The infographic on the left shows not only the time saving way of Strep-tag® protein purification but also the main key features of the Strep-tag® system at a glance.
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.