Flow cytometry analysis of BM or FL cells from STAT5ab^−/− and wild- type mice for Sca-1⁺c-kit⁺lin⁻ or lin⁻ SP fractions.

Total BM cells were harvested from individual STAT5ab^−/−or wild-type mice. FL cells were collected from pregnant females that were mated 14.5 days earlier. The cells were then blocked with normal mouse serum, stained with antibody cocktails, and analyzed by FACS. (A) Shown are representative FACS profiles for lineage-negative BM or FL cells, analyzed for coexpression of Sca-1 (FITC) and c-kit (PECy5). (B) Shown is analysis of FL cells stained first with Hoechst 33342, washed, and next stained with antibodies to cell surface markers. Representative FACS profiles for c-kit⁺lin⁻SP and Sca-1⁺lin⁻SP cells are shown. The percentages marked represent the c-kit⁺lin⁻ or Sca-1⁺lin⁻ cells falling within the SP region (box).