Flow cytometry of the urinary bladder.

Flow cytometry now appears sufficiently developed technically to identify carcinoma of the bladder on irrigation specimens with accuracy comparable to that of conventional exfoliative cytology. The cancer cells are distinguished by abnormal levels of DNA per cell, which can be quantified with acridine orange, a metachromatic fluorescent dye for DNA and RNA. With this technique it is also possible to follow the development of carcinoma and assess the effects of treatment by quantifying the number of cancer cells present in the irrigation specimen.