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Streptamer® technology for fluorescent cell staining & magnetic cell isolation

Uncompromised, authentic cells for research and diagnostics - watch video (in German)

The Streptamer® technology allows both fluorescent staining as well as magnetic isolation of cells with reversible reagents. Virtually all eukaryotic cells can be selected with this technology. The reversible Streptamers® not only show excellent staining intensities, but they can be removed from the cells to optimally preserve cell effector function, making it a versatile platform, not only for basic research, but also for safe and efficient diagnostic use.

Fab Streptamers®

are designed for the selection of lymphocytes carrying a surface marker which defines a cell subset, e.g. T cells (CD3, CD4, CD8), memory T cells (CD8, CD62L, CD45RA-) and regulatory T cells (CD4, CD25, CD45RA). Magnetic isolation is performed with microbeads and a hand-held magnet. For fluorescent staining, Strep-Tactin PE or APC for Fab Streptamers is offered.

MHC I Streptamers®

are designed for the selection of antigen-specific CD8+ T cells. Magnetic isolation is performed with nanobeads and magnetic columns. For fluorescent staining, Strep-Tactin PE or APC for MHC I Streptamers® is offered.

Magnetic cell isolation (Fab Streptamers®):

Fluorescent cell staining (MHC I Streptamers®):

The Streptamer® principle: full reversibility

Low affinity Strep-tagged Fab fragments or MHC molecules are multimerized with Strep-Tactin®, a streptavidin derivative, to generate multimers with high binding avidity.  Strep-Tactin® fluorochromes are used for cell staining / FACS isolation and Strep-Tactin® magnetic beads are used for magnetic cell isolation. Upon addition of low concentrations of d-biotin (Vitamin H), which competes with high affinity for the binding of Strep-tag to Strep-Tactin®, staining and isolation reagents dissociate rapidly from the cell surface.
This reversibility enables multiple cell stainings with different Strep-Tactin® fluorochromes as well as sequential positive cell selections with magnetic beads.

The Streptamer® reagents: a modular system

Fab-Streps or MHC-Streps are either combined with fluorescence- or bead-labeled Strep-Tactin® for cell staining or magnetic isolation, respectively. Biotin is offered as stock solution with the Streptamer® Solution Set which is used for removal of cell staining as well as cell isolation reagents. This modular reagent system enables the economic generation of multiple receptor- or antigen-specific staining and isolation reagents. All reagents can be purchased as single products or assembled in ready-to-use staining and isolation kits.