For isolation of CD8+ CD62L+ CD45RA+ naive T cells from peripheral blood mononuclear cells. The kit includes all Fab Streptamer components for a triple positive selection of cell subsets with magnetic microbeads* and for removal of Streptamers from isolated cells. 1.) Strep-Tactin(R) Magnetic Microbeads for Fab Streptamers; 4 vials for 5x10^8 cells each 2. ) CD8 Fab-Strep human for isolation of T-cells; 1 vial for 1x10^9 cells 3.) CD62L Fab-Strep human for isolation of T-cells; 1 vial for 5x10^8 cells 4. ) CD45RA Fab-Strep human for isolation of T-cells); 1 vial for 5x10^8 cells 5.) D-Biotin stock solution for Streptamer(R) technology; 3x 1 ml 6. ) Buffer IS, Streptamer(R) Washing Buffer, 10x concentrated; 2x 50 ml This product requires dry ice shipment and is shipped directly from our Headquarters in Germany. *Microbeads are intended for use with a permanent magnet for manual cell isolation; we recommend our StrepMan magnet for 2 x 15 ml and 2 x 50 ml Falcon tubes. Principle of Selection: Isolation of human CD8+ CD62L+ CD45RA+ naive T cells is performed by serial triple positive selection. In a first step PBMCs are labeled with magnetic CD8 Fab Streptamers. Labeled cells are isolated in a strong magnet (StrepMan, horizontal position) where they migrate toward the tube wall on the side of the magnet. This CD8 positive cell fraction is collected and cells are liberated from all labeling reagents by addition of biotin in a strong magnet (StrepMan, upright position). The magnetic Streptamers migrate toward the tube wall and the label-free cells remain in the supernatant. Biotin is removed by washing. The pure and label-free CD8 positive cells are subjected to a second positive selection with magnetic CD62L Fab Streptamers following the same procedure. The CD8+ CD62L+ T cells are then subjected to a third positive selection with CD45RA Fab Streptamers. The resulting cell preparation is highly enriched with CD8+ CD62L+ CD45RA+ naive T cells with a purity of more than 90%. No depletion steps and no columns are needed.