Dispersion Staining

an optical staining technique in which colors are produced by the differential refraction of different wavelengths of light due to mounting the sample in a liquid having a different dispersion of refractive index.
Discussion—The procedure employs central or annular stops placed in the objective back focal plane of a microscope. Using an annular stop with the substage iris closed, a fiber mounted in a high dispersion medium shows a colored boundary of a wavelength where the fiber and the medium match in refractive index. Using a central stop, the fiber shows colors complementary to those seen with an annular stop.