Strep-Tactin® Magnetic Beads are polysaccharide coated magnetic microspheres covalently linked to Strep-Tactin®. The paramagnetic beads enable a rapid and economic T-cell isolation at 4 °C under sterile conditions. The nanobeads are designed for cell isolation with Milteny columns/machines. For isolation of antigen-specific CD8 T-cells, Strep-Tactin® Magnetic Beads have to be combined with MHC I-Streps, antigen-loaded MHC I containing the Strep-tag® affinity tag. After isolation of T-cells on e.g. a Miltenyi Biotec MACS column, Strep-Tactin® Magnetic Beads can be mildly dissociated from the MHC I-Streps using biotin. The monomeric MHC I-Streps then spontaneously dissociate from the T-cell receptor due to its very weak binding. The rapid and complete dissociation of all Streptamer® reagents from the T-cells assures full functionality of the isolated cells. Due to the reversibility, the cells can be sequentially positively isolated with different MHC I-Streps. 1 prep is sufficient to purify T-cells out of a total of 2x107 cells.