For isolation of CD4+ CD62L+ CD45RA- central memory T cells from peripheral blood mononuclear cells. The kit includes all Fab Streptamer® components for double positive selection and for one depletion of cell subsets with magnetic microbeads*and for removal of Streptamers from isolated cells.

1.) Strep-Tactin® Magnetic Microbeads for Fab Streptamers; 4 vials for 5x10^8 cells each

2.) CD4 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® technology; 3x 1 ml

6.) Buffer IS, Streptamer® 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 CD4+ CD62L+ CD45RA- central memory T cells is performed by serial double positive selection and one depletion step. In a first step PBMCs are labeled with magnetic CD4 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 CD4 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 CD4 positive cells are subjected to a second positive selection with magnetic CD62L Fab Streptamers following the same procedure. The CD4+ CD62L+ T cells are then subjected to a depletion step with CD45RA Fab Streptamers. The resulting cell preparation is highly enriched with CD4+ CD62L+ CD45RA- central memory T cells with a purity of more than 90%. No columns are needed.