Other proteins colocalize with CD20 in the cap. (A) Daudi/CD20-GFP and (B) primary B cells were incubated with 10 μg/mL rituximab or rituximab-AF633, respectively, for 1 hour and then fixed and stained for ICAM-1, CD45, CCR7, moesin, or biotinylated as indicated followed by incubation with secondary fluorescently labeled antibodies. As a positive control in Daudi/CD20-GFP cells, CD20 was targeted by rituximab AF633 and colocalization between green and red fluorescent channels was calculated (A). As a positive control, primary B cells were additionally stained for CD20 using an antibody recognizing the cytoplasmic portion of the protein followed by incubation with secondary fluorescently labeled antibody (B). Scale bars represent 5 μm. (C-D) Pearson’s correlation coefficients calculated for colocalization of CD20 and other cell components as indicated in individual Daudi (C) or primary B cells (D) are shown. A total of 18 to 46 cells were analyzed per condition.