Movie 2

Antigen colocalises with acidic vesicles soon after internalisation. A20 D1.3 cells were loaded with LysoTracker (middle panel) and activated with AF488-αIgM (left panel). Right panel shows merge image of antigen channel (magenta) and LysoTracker channel (cyan). Liveimaging was performed with SDCM (EVOLVE camera) on a single plane every 500 ms. Doublepositive vesicles are highlighted with a purple circle tracking the spots in the antigen channel. Movie was recorded 1 min after cell activation.