Expression of c-kit protein in CMCs and skin mast cells. (A) Flow cytometry of the surface expression of c-kitprotein in CMCs derived from +/+, mi/mi,Mi^or/Mi^or, andMi^wh/Mi^wh mice. Cells were incubated with either ACK2 MoAb or negative control antibody. (B) The representative field showing the content of c-kit protein in skin mast cells of day-18 pc embryos or 20-day-old mice. Specimens were observed by the confocal laser scanning microscope after staining c-kit protein with ACK2 MoAb. At least 20 fields were examined in three tissue samples obtainied from different mice, and comparable results were obtained. The intensity of fluorescence is shown by colors (the upper is the stronger). (Original magnification × 2,500.)