Immunofluorescence and flow cytometric analysis of GFP expression in tissue-resident macrophage populations. Immunofluorescence analysis for endogenous GFP expression in frozen tissue sections of (A) liver and (B) lung from CD68-GFP and WT mice. Flow cytometric analysis of GFP expression in (C) Kupffer cells (CD45⁺/CD11b⁺/F4/80⁺). (D) Microglia (CD45⁺/CD11b^Int+), (E) alveolar macrophages (CD45⁺/CD11c⁺/Siglec-F⁺/F4/80^Int+) and (F) splenic macrophages (CD11b⁺/ F4/80⁺) from CD68-GFP and WT mice. Results are representative of 3 mice per group.