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 a reversible technology, i.e. staining and isolation reagents can be removed from the cells which optimally preserves cell effector function. This makes the Streptamer® technology a versatile platform not only for basic research but also for save 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.

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.