VISUAL DEMONSTRATION OF THE PATTERN OF LIGHT-INDUCED ELECTRIC-FIELD ON THE SURFACE OF DRIED ORIENTED BACTERIORHODOPSIN SAMPLES

Continuous illumination of a dried oriented sample of the purple membrane of Halobacterium halobium induces a steady-state charge separation inside the membranes. The genenerated electrostatic field was demonstrated by the accumulation of the grains of toner used in the copying machines. At low light intensity, the pattern of the adhered toner follows the shape of the illuminating laser beam. At higher intensity the exposed area becomes blue. This blue form apparently has no charge separation process, since in this instance the toner forms a ring on the contour of the illuminated area.