In vivo localization of injected carcinogen by fluorescence quartz rod microscopy.

A technic whereby carcinogenic hydrocarbon particles injected into living animals can be identified by fluorescence microscopy of living lung fields is described. The meth od utilizes high pressure mercury light sources, with appropriate filters at the source and microscope optics for fluorescence examination; a quartz rod as light carrier to the lung field; and special thoracotomy on living rats and rabbits for exposure of the area to be examined. The particles stood out wherever localized as long as 5 months after injec tion. They could be studied by display on a television camera and photography of the monitor image. Film was too slow for in vivo instant recording. Damage, as revealed by ordinary microscopy, was not very obvious, and further in vivo methodology to detect alterations in the physicochemical nature of areas involved is suggested. Liver, spleen, kidney, brain, muscle, bone marrow, and skin also revealed the particles after post mortem fresh examination.