Proliferation of mitochondria during the cell cycle of the human cell line (HL-60).

Using rhodamine 123 to stain mitochondria of the human cell line HL-60, we have followed their increase over the cell cycle by flow cytometry. A near-linear synthesis of mitochondrial mass was shown to occur over the cell cycle. A comparison with the cell's DNA synthesis pattern obtained by the same technique established a common time-base. The mitochondrial synthesis curve changes with culture age. As a control, thd dye was tested for its binding specificity and for its use to resolve mitochondria microscopically. Its stoichiometric range was established and, above 0.25 microgram/ml, it was shown to reduce growth rate and cell viability in culture.