Northern and Western blot of PU.1, Elf-1, c-jun, and c-fos. (A) Northern blot of total RNA from mature neutrophils and the 3 MACS-depleted populations of neutrophil precursors. The blot was hybridized with probes against PU.1, Elf-1, c-jun, and c-fos (B) Schematic representation of the hybridization intensities from panel A as in Figure 4. (C) Western blot of PU.1, Elf-1, c-jun, and c-fos. Equal loading was assessed by probing with an antibody against α-tubulin (not shown). The arrows indicate the bands of the target proteins.