PMA treatment increases pH to 6.5–7.5 in a subset of lysosomes. Lysosomal pH in untreated cells is below 4.5 as shown on the left image. In PMA-treated cells, pH was significantly elevated to as high as 6.5–7.5 in only a subset of lysosomes as indicated by the arrow, while the pH of other lysosomes were essentially unaffected. Nu, nucleus. Bar, 10 μm.
Chen BMC Cell Biology 2002 3:21 doi:10.1186/1471-2121-3-21