Fig. 2. L6-Ag is found in late endocytic organelles. MDA-MB-231 cells were grown on glass coverslips, fixed with 2% paraformaldehyde and permeabilised with 0.1% Triton X-100. Immunofluorescence staining was carried out using mouse mAb to human L6-Ag (IgG2a) in combination with mouse mAbs to proteins localised to various intracellular compartments (all IgG1): EEA1, early endosomes; LBPA, late endosomes; Lamp1, late endosomes/lysosomes. Staining was visualised using Alexa-Fluor-594-conjugated goat anti-mouse IgG2a Ab (red) and Alexa-Fluor-488-conjugated goat anti-mouse IgG1 Ab (green). Shown are representative images acquired using a LSM510 microscope. Note that, after permeabilisation, surface pools of L6-Ag and CD63 are almost completely lost. Scale bar: 10 µm.