Casida L E
Science. 1968 Jan 12;159(3811):199-200. doi: 10.1126/science.159.3811.199.
A microscopic procedure employs infrared color photography to enable visualization of unstained microorganisms in natural habitats. The procedure can be used for either living or dead microorganisms; it enables visualizaion of microbial cells embedded within component materials of the habitat.