In situ detection, isolation, and characterization of c-kit+ cells. (a) c-kit+ cells (green, inset) in a normal adult mouse lung. (b) An example of c-kit+ cell (green, arrow) and CD45+ cell (red, arrowhead). (c) FACS scatter plots showing the expression of c-kit in a population of small lung cells. (d) Expression of c-kit (green) on sorted cells shown by immunocytochemistry. (e) FACS analysis of c-kit sorted cells showing lack of expression of hematopoietic lineage marker CD45. Scale bars, (a) 50 μm, (b) 5 μm, and (d) 20 μm.