Comparative flow cytometric analysis of GFP expression in blood, bone marrow, and spleen of CD68-GFP and CX₃CR1^GFP mice. (A) The gating and staining strategy used to characterize various leukocyte populations (spleen was used to set antibody panel; isotype controls used are listed in “Methods”). (B-C) Monocytes from blood, bone marrow, and spleen displayed GFP expression in both CD68-GFP and CX₃CR1^GFP mice. WT mice were used as negative controls for GFP expression and shown overlaid as red dots (B). (D-E) CD68-GFP mice express GFP in a subset of bone marrow/blood neutrophils and splenic DCs, but expression was absent in lymphocytes. (Representative flow cytometry plots are shown; analysis was carried out in 3 to 4 mice.)