Qiagen, 34850, Strep-tag Antibody (100 μg)

Mouse monoclonal antibody that recognizes the Strep-tag II epitope; lyophilized, for 1000 ml working solution

Features

- Excellent results in dot- and western-blotting procedures
- Highly sensitive and specific detection

Principle

The Two-Step Affinity Purification System, which is based on the proven 6xHis tag and the short Strep -tag II, enables simple and highly efficient purification of ultrapure proteins in a fast and standardized procedure. Recombinant proteins carrying both tags are purified sequentially on Ni-NTA and Strep -Tactin matrices (see figure Ultrapure protein in two steps ). The two simple affinity purifications provide fully active, full-length, ultrapure protein, suitable for any downstream application.

Procedure

Recombinant proteins that carry two small affinity tags (the 6xHis tag and Strep -tag II) are efficiently expressed in E. coli , insect, or mammalian cells using pQE-TriSystem His· Strep vectors. After cell lysis and clearing of the lysate, proteins are initially purified using an immobilized-metal affinity chromatography procedure that is based on the proven 6xHis-tag-Ni-NTA interaction. After elution from the Ni-NTA matrix using imidazole, recombinant proteins (which also carry the Strep -tag II epitope) are loaded directly onto a Strep -Tactin matrix. No buffer exchange is required. Protein is eluted from the Strep -Tactin matrix using either biotin or desthiobiotin. This two-step affinity purification delivers ultrapure (>98% pure) protein (see figure Two-step affinity purification procedure ). The order of purifications can be reversed (i.e., Strep -Tactin followed by Ni- NTA purification). Proteins can be detected with high specificity and sensitivity using mouse monoclonal Strep -tag or Anti·His antibodies.

Applications

- Structural and functional analyses
- Expression in eukaryotic systems

The two-step affinity purification system, using the Strep- tag Antibody for detection, is highly suited for applications where high purity is at a premium or is difficult to achieve. The standardized purification procedure also increases throughput by eliminating the need for protein-specific purification protocol development and optimization. The ultrahigh purity and convenience provided by the two-step affinity purification system make it the method of choice for: