Purification of hematopoietic stem cells. Bone marrow cells from the CD45.1 mice were first depleted of red blood cells. Red blood cell-lysed bone marrow cells were then enriched for c-Kit⁺ cells by positive selection using magnetic beads. c-Kit⁺ bone marrow cells were subsequently stained with a cocktail of monoclonal antibodies, including anti-c-Kit, anti-Thy1.1, anti-Sca-1, and anti-lineage cell markers (CD3, CD4, CD5, CD8a, CD11b, B220, Gr-1, and TER-119). The stained samples were finally sorted for c-Kit⁺Thy1.1^lowLin^-/lowSca-1⁺ (KTLS) cells (purified hematopoietic stem cells) using a FACS machine. The figure shows the procedures and quality of samples for each step. BM indicates bone marrow; KTLS, c-Kit⁺Thy1.1^lowLin^-/lowSca-1⁺ hematopoietic stem cells; Lin, lineage; APC, antigen-presenting cell; and CD45.1 mice, C57BL/Ka, CD45.1, Thy1.1 mice.