Immunophenotypic characterization of immunomagnetically sorted CECs by means of Dynabeads in MM patients with 13q14 deletion. In simultaneous double fluorescence staining experiments, CECs coexpress VEGFR-2 (positive green staining for anti-VEGFR-2 antibody) (A) and VWF (positive red staining for anti-VWF monoclonal antibody) (B), and CD144 (positive green staining for anti-CD144 monoclonal antibody) (C) and VWF (positive red staining for anti-VWF monoclonal antibody) (D). Immunomagnetically sorted CECs do not coexpress VWF (positive green staining for anti-VWF monoclonal antibody) (E,G) with plasma cell-associated markers CD38 (negative red staining for anti-CD38 monoclonal antibody) (F) and CD138 (negative red staining for anti-CD138 monoclonal antibody) (H). In patients with MM, immunomagnetically sorted CECs do not express CD45 (negative green staining for anti-CD45 monoclonal antibody) (I) and CD14 (negative red staining for anti-CD14 monoclonal antibody) (L). Note that several Dyna-beads are attached to the cells and that beads present red or green staining depending on the filter used for fluorescence analysis. White arrows indicate CECs: cell nuclei have been counterstained with DAPI II (blue staining). Scale bars equal 10 μm.