Fig. 1. CDβgeo Sca1⁺ cells are capable of self-renewal and expansion. (a) CDβgeo cells were stained with FITC-conjugated antibody against Sca1, and analyzed by flow cytometry. Two populations can be distinguished based on Sca1 fluorescence: Sca1⁺ 13.1%; and Sca1^- 67.4%. (b) Cells were sorted into Sca1⁺ and Sca1^- populations directly into 96-well plates containing growth-factor-reduced Matrigel at 500 cells/well, and clones were counted after 10 days. The Sca1⁺ cells gave rise to 47±14 colonies in Matrigel, whereas the Sca1^- produced no colonies. Colonies were stained with Crystal Violet and counted by two independent researchers. (c) CDβgeo Sca1⁺ population give rise to 75±4.2% Sca1⁺ and 24±4.1% Sca1^- cells. (d) CDβgeo Sca1^- cells remained mostly Sca1^- after culture, and gave rise to 94±1.5% Sca1^- cells and only 6±1.45% Sca1⁺ cells.