X-ray analysis of retinal photoreceptors.

A series of low-angle X-ray reflections have been recorded from photoreceptors in four types of intact untreated retinae. The retinae were maintained in a living condition during the X-ray exposure. The X-ray reflections arise from the regular arrangement of disk membranes within the photoreceptors. The recorded X-ray intensities contain information on the onedimensional electron-density distribution of the photoreceptors. An electrondensity model which is in good agreement with the low-angle X-ray data has been derived.