Study of microscopic porphyrin fluorescence

A technique of porphyrin (hematoporphyrin derivative [Hpd]) fluorescence microscopy was evaluated by studying Hpd uptake, retention, and loss in established human cancer cell lines. Hpd uptake appeared to be qualitatively identical in the three cell lines used, but the rate of loss was slowest in the renal-carcinoma-derived line, suggesting a cellular characteristic. The technique was readily applied to demonstrate porphyrin fluorescence in exfoliated cells in urine of bladder cancer patients.