Cytochemistry and phenotype of freshly isolated CD15⁺CD14^- cells. (A) Photographs of May-Grünwald-Giemsa–, MPO-, and double-specific/nonspecific esterase–stained cytospin preparations; original magnification, × 400. (B) Nuclear DNA analysis of CD15⁺CD14^- cells was performed using a FACSCalibur flow cytometer. HPB-NULL cells were used as controls. Cell cycle distribution of HPB-NULL cells was as follows: with G₁ phase, 42.9%; S phase, 30.5%; and G₂/M phase, 26.6%. (C) The expression of CD15/CD14, MPO, M-CSFR, lactoferrin, mannose receptor, and HLA-DR was analyzed using a FACSCalibur flow cytometer. In the histograms, the thick and thin lines show the expression of the indicated molecules and isotype controls, respectively. Representative data from 5 independent experiments are shown.