FIGURE 5.

LAT clusters do not colocalize with FcεRI at the synapse. A. Membrane sheets from IgE primed cells settled onto mobile (top) or immobilized (bottom) ligand for six minutes and labeled for FcεRI β (12 nm gold) or LAT (6 nm gold). LAT clusters are circled with thin lines on each sheet to indicate general cluster size and location relative to receptors (circled with thick lines). Scale bars are 100 nm. Ripley’s tests for coincidence of LAT and FcεRI β label are inset in each figure. B. Paraformaldehyde fixed IgE^DNP-primed RBL-2H3 cells settled onto 25 mol% DNP-lipid (top row) or DNP₂₄-BSA (bottom row) surfaces for 6 minutes. After permeabilization, cells were dually labeled for phosphorylated LAT (AF555) and FcεRI β (Cy5; psuedocolored). Images are contrast enhanced.