WASP expression by RT-PCR analysis in differentiated and committed hematopoietic cell populations. (A) Representation of the staining and sorting gates of cultured cells. The culture of hematopoietic progenitors with various cytokines (as described in Materials and Methods) allowed the generation of different populations: the granulocytic sorted as CD15⁺CD14⁻; the monocytic and dendritic sorted, respectively, as CD14⁺CD1a⁻ andCD1a⁺CD14⁻; the megakariocytes defined as CD41⁺CD33⁻; and the erythroid-committed, glycophorin A⁺CD71⁺ (GLY-A⁺). The open squares indicate the sorting regions. (B) RNA from FACS-sorted cell cultures (A) was processed as described and RT-PCR analysis was applied. PCR products for WASP (900 bp) or G3PDH (300 bp) were shown by hybridization as described above. As negative control, H₂O was added instead of DNA in the PCR amplification.