Variation in U.V. primary fluorescence-intensity of vital cells depending on 60Co gamma-radiation dose

Using impulse-cytofluorophotometry in the ultra-violet spectral region the author has shown on vital, unstained Ehrlich ascites tumour cells that the primary fluorescence intensity of this tumour is on day 11 after transplantation 20 per cent higher than on day 8. Storage of the vital cells for 25 min at 20 degrees C has no effect on this result. When the cells are exposed to 60Co to gamma-radiation on day 6, a new stable fluorescence level is established afted 20 hours. Measurements of the primary fluorescence intensity depending on dose have shown a significant rise starting from 75 rad at 48 hours after irradiation. The fluorescence intensity rises by 42.5 per cent of the control value at 3000 rad, but only by 31.5 per cent on exposure to 4000 rad.