-dextran labels late endosomes/lysosomes in WT and
mouse astrocytes. Fluorescence images of WT (a) and GFAP
-/- (b) astrocytes labeled with dextran and immunostained with antibodies against LAMP1, a marker of late endosomes/lysosomes. Merged images (overlay) show that the majority of dextran puncta are colocalized with LAMP1 puncta. Lower panels (insets) show boxed regions at higher magnification. Scale bars: 10 μm, 2 μm (insets). Arrowheads point to typical structures expressing both signals. Note that the green signal corresponding to the membrane bound LAMP-1 signal encircles the luminal signal of red dextran.