Strep-tag Antibody (100 µg)

From QIAGEN, this antibody is designed for highly sensitive and specific detection of Strep-tagged proteins. It recognizes the SAWSHPQFEK epitope and supports a broad range of applications, including Western blot, dot blot, ELISA, immunoprecipitation, and immunohistochemistry. A secondary antibody is required for detection, and in Western blots using chemiluminescent detection the sensitivity is 1 ng.

The reagent is a key element of the Two-Step Affinity Purification System, which combines the proven 6xHis tag with the short Strep-tag II to deliver ultrapure (>98% pure) protein. Recombinant proteins carrying both tags can be 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 captured on a Ni-NTA matrix and eluted with imidazole before being loaded directly onto a Strep-Tactin matrix, with no buffer exchange required. Elution from the Strep-Tactin matrix is achieved using biotin or desthiobiotin, and the order of the two affinity steps can be reversed.

Because purification is performed under native conditions, the system is well suited to highly demanding downstream applications such as crystallization studies. The standardized protocol removes the need for protein-specific purification development and optimization, while mouse monoclonal Strep-tag or Anti·His antibodies can be used to confirm proteins with high specificity and sensitivity.