Fig 3. Evaluating synaptic vesicle-like properties of CCVs.

(A) Identical PDVF Western blots containing the enriched CCV sample were probed with antibodies against either Synaptotagmin or Synaptophysin. (B) CCV acidification was tested in the presence of glutamate using the acridine orange acidification assay with CCVs in a 4 mM KCl buffer. Marked are additions of 1 mM ATP, 1 mM glutamate (Glut), and 150 mM KCl (KCl) (final concentrations). (C) CCV acidification using the same conditions as (B) except the starting buffer contained 0, 2, or 4 mM KCl (black, blue, and red traces, respectively).