Figure 3.

The anti-BCR immuno-gold-labeling is specific. (A) The Monte-Carlo simulations were performed for two possible BCR oligomer geometries: a linear and a laminar geometry. (B) J558Lδm/mb-1flN cells expressing the wt IgD-BCR (black line), J558L cells without any BCR (dark gray line) or IgD-hSbap BCR-expressing J558L (light gray line) were labeled with the anti-BCR antibody Ac146 and subsequently stained with FITC-labeled anti-mouse IgG or gold-coupled anti-mouse IgG antibodies. Fluorescently labeled cells were analyzed by flow cytometry, and mean fluorescent intensities (MFI) of the gated populations are given. Gold labeled cells were subjected to replica preparation and analyzed by TEM. The mean gold particle (MGP) number detected on the cell replicas confirms specific labeling of the BCR on wt and IgD-hSbap expressing J558L cells, while immuno-gold-labeling of J558L not expressing BCR does not result in significant gold particle detection on surface replicas.