Fig. 5.

Colocalization of CTB with EEA1 and Lysotracker. For colocalization with Lysotracker (LT), synoviocytes were incubated for 3 h at 37°C in the presence of Alexa 488-conjugated CTB. During the last 1 h of incubation, Alexa 594-conjugated Lysotracker was added to the culture medium. For colocalization with EEA1, synoviocytes were incubated for 30 min at 37°C in the presence of Alexa 488-conjugated CTB. After cooling to 4°C, the cells were fixed and permeabilized before labeling with an EEA1 antibody, followed by an Alexa 594-conjugated secondary antibody. No colocalization between CTB and either the early endosomal- or the lysosomal marker was observed