Strep-Tactin(R) APC

Strep-Tactin(R) conjugated to either R-Phycoerythrin (PE) or Allophycocyanin (APC) is suitable for staining or isolation of antigen-specific cytotoxic T cells (MHC I Streptamer(R)) or surface marker-specific cells (Fab-TACS(R)/Nano-TACS(R)) based on our Strep-tag(R) technology. To target specific cells, MHC I complexes, low affinity Fab fragments or nanobodies fused to a Twin-Strep-tag(R) (MHC I-Streps, Fab-Streps or Nano-Streps) are required in addition to fluorescent Strep-Tactin(R). Strep-Tactin(R) multimerizes MHC I-Streps or Fab-/Nano-Streps, ensuring stable binding to cells. The resulting fluorescent complexes can be used to stain cells that are specific for the respective peptide-loaded MHC I molecule or for a selected surface marker. The addition of biotin reverses the multimerization and causes the dissociation of MHC I-Streps or Fab-/Nano-Streps from the cell surface. The complete removal of all labeling reagents preserves the cells' full biological activity.