FACS mononuclear blood cells and co-culture analysis and sorting. Cytograms and histograms obtained using FACS Aria II (Becton Dickinson, USA). (A) The cytogram of mononuclear cells obtained from canine blood after the Accuspin System-Histopaque 1077 centrifugation. The monocytes were gated based on the morphological criteria (SSC v/s FSC cytogram). (B) Histogram of CD64 stained leukocytes: CD64 negative (CD64-) leukocytes showed low FITC signal, whereas CD64 positive (CD64+) leukocytes showed high FITC signal. (C) The cytogram of CD64-positive cells showing antibodies specificity to monocytes. (D) Histogram of the fluorescence intensity of unstained macrophages grown as a single culture. (E) Histogram of the fluorescence intensity of CMTMR-stained cancer cells grown as the single culture. (F) Histogram and sorting gates of unstained macrophages and CMTMR-stained cancer cells grown as a co-culture for 72 hrs.