Splenocytes contain an autofluorescent cell population of the monocyte/macrophage lineage. (A) Representative flow cytometry plots of unstained single-cell suspensions of splenocytes (left) and blood leukocytes (right) showing an autofluorescent cell population in splenocytes but not in blood. Another consistent feature of splenocytes is the large proportion of lymphocytes, which are in part larger than blood lymphocytes. Percentages are indicated, figure is representative of n = 82 spleens. (B) MFIs for allophycocyanin (APC) and peridinin-chlorophyll protein-Cy5.5 (PerCP-Cy5.5) in unstained samples, comparing the autofluorescent cells in the spleen and spleen monocytes gated as in panel A, with blood monocytes, M-CSF Mφ, and GM-CSF Mφ cultured monocyte-derived macrophages. (C-F) Stainings of CD45, CD14, CD33, and CD36 on various cell types in spleen and blood. Mean ± standard error of the mean (SEM) of n ≥ 8 are shown for each group. FSC, forward scatter; MFI, median fluorescence intensity; Δ MFI, MFI corrected for staining with an isotype control; M-CSF Mφ , monocyte-derived macrophages cultured for 9 days with M-CSF; GM-CSF Mφ, monocyte-derived macrophages cultured for 9 days with GM-CSF; SSC, side scatter.