Application of malachite green‐containing glutaraldehyde as a fixative for electron microscopy of xanthophores in the medaka, a Teleostean Fish

In xanthophores of the medaka, Oryzias latipes, numerous electron-dense granules of varying sizes ranging from 0.2 um to 0.5 um are encountered after fixation of tissues by a malachite green-containing glutaraldehyde. These granules are never observable in tissues prepared by conventional glutaraldehyde fixation, and they are considered to be lipid in nature and contain carotenoid pigments.