The following antibodies were used: mouse anti-tubulin (clone DM1A) (Sigma), rabbit anti-synaptophysin (Roche Molecular Biochemicals, Indianapolis, IN), fluorescein-conjugated anti-mouse IgG, and ...

In the secretory pathway, the pH within organelles is gradually acidified, starting at 7.1 to 7.2 in the endoplasmic reticulum, decreasing to 6.0 to 6.7 in the Golgi apparatus/trans-Golgi network ...