CD11b, Siglec-F, and CCR3 coexpression defines a highly specific murine eosinophil population by flow cytometry. Peripheral blood from CD2-IL-5–transgenic BALB/c mice was stained with anti–CCR3-PE, anti–Siglec-F-PE, and CD11b-APC antibodies followed by 7-AAD and sorted for CD11b⁺/CCR3⁺/low and CD11b⁺/Siglec-F⁺/low populations in 7-AAD^– cells. Cytospins were prepared from sorted cells and were stained with Diff-Quick (optical magnification × 500).