Expression analysis of the Arf/GFP allele in freshly isolated and cultured murine BM cells. (A) Freshly isolated BM cells were stained with c-kit1-allophycocyanin (APC), Sca1-PE, and a mixture of FITC-conjugated antibodies against mature lineage markers (CD4, CD8, B220, Gr1, and Mac1). The top row shows analysis of BM cells from wild-type BL6 mice and the bottom row from Arf^GFP/+ mice. The left column shows GFP expression in a gated Lin^– fraction and the right from cells gated on the Lin^–c-kit⁺Sca1⁺ phenotype. (B) After 12 days of culture, BM cells from ArfGFP/+ mice were stained with c-kit-APC, Sca1-PE, and Lin-FITC antibody cocktail. The top row shows analysis of BM cells from wild-type BL6 mice and the bottom row from Arf^GFP/+ mice. As before, Lin^– and c-kit⁺Sca1⁺Lin^– (KSL) cells were gated and analyzed. Positions of gates and percentage of gated cells are shown.