A simple fluorescence technique for light microscopy of the crystalline lens

Lenses fixed in formaldehyde or glutaraldehyde can be embedded in plastic, and sections as large as 3-4 mm across can be cut with glass knives on an ultramicrotome. When these sections are stained with 25% sodium fluorescein and allowed to bleach in a fluorescence microscope, high contrast images of essentially every cell in the section, including cells very near the lens center, can be seen. The method is effective with lenses from a number of species, and should be useful for a wide variety of morphological studies of normal and cataractous lenses.