(A and B) Human B cells transfected with plasmids expressing either WT PLC-γ2-GFP or Δ20–22 PLC-γ2-GFP were labeled with DyLight 649-Fab anti-IgM, placed on anti-IgM bilayers for 5 or 15 min, fixed, stained with antibody specific for pCbl (Tyr700), and imaged by TIRF microscopy. (A) Representative TIRF images for the BCR (red) and pCbl (green), as well as merged images are shown. (B) Left: Means ± SEM of the MFI of pCbl. Right: Pearson’s colocalization coefficients for the BCR and pCbl. Each data point represents the values from a cell analyzed in one of two independent experiments. Statistical analysis was performed by ANOVA.