Ultra-Violet Damage to Living HeLa Cells as Recorded by Time-Lapse Motion Picture Studies. ∗

Abstract

Summary

1. When living HeLa cells are continuously irradiated by ultra-violet emitting cathode ray scanner tube, no ultra-violet damage can be detected when low scanner tube beam currents are used. 2. When the beam current is increased, dividing cells show (a) inability to complete mitosis, (b) increased syneresis during mitosis, and (c) decreased cytoplasmic bubbling during mitosis. 3. With a similar beam current, intermitotic cells show (a) cessation of pinocytosis, and (b) cessation of Brownian motion of cytoplasmic lipid droplets, even though no change occurs in the absorption image or the structural image of the cell. 4. When the beam current is further increased, intermitotic cells show a sudden generalized increase in absorption followed immediately by a marked contraction of the cell into a small round intensely absorbing mass.