Click on image to view larger version.

Fig. 3. Giant endosomes do not correspond to lysosomes. To further demonstrate the
nature of the giant endosomes in rab5(Q79L) expressing macrophages, cells were
incubated with 16 nm BSA-gold for 30 minutes, followed or not by a 16 hours
chase period. After an internalization of 30 minutes (A), BSA-gold particles
were found in large endocytic organelles (e). As in the kinetic experiment
with the fluid phase tracer, a longer chase period (16 hours) resulted in the
transfer of the BSA-gold particles to smaller electron dense vesicles (l) (B),
while large vacuoles now devoid of BSA-gold particles could be observed. Bars,
100 nm.