Abstract
A combined cytochemical and electron microscopic demonstration of acid phosphatase activity of melanosomes in melanocytes was carried out on B-16 and Harding-Passey mouse melanoma and the retinal pigment epithelium of white leghorn chick embryos. The presence of histochemically detectable acid phosphatase activity in the melanosomes was clearly demonstrated. The parallel relationship between melanization and the acid phosphatase activity was observed. The maturation of the melanosome is supposed to relate some what to the lysosome, which is specifically marked by the presence of acid phosphatase activity in the cell.
