Streptamer® technology for cell staining and cell isolation
Uncompromised, authentic cells for research, diagnostics and clinical use - watch video (in German)
The Streptamer® technology allows both fluorescent staining as well as magnetic isolation of cells. Virtually all eukaryotic cells can be stained and isolated with this technology. It is reversible, i.e. staining and isolation reagents can be removed from the cells, which optimally preserves cell effector function, making it a versatile platform, not only for basic research, but also for safe and efficient clinical use.
Fab Streptamers are designed for magnetic isolation (and fluorescent staining) 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).
MHC I Streptamers are designed for fluorescent staining and magnetic isolation of antigen-specific CD8+ T cells.
Fab Streptamer® reversible staining procedure:
MHC I Streptamer® reversible staining procedure:
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.
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.