Improved staining of leprosy bacilli in tissues.

A technique which reliably demonstrates Mycobacterium leprae, M. tuberculosis and fungi in tissues is described. It is based on the oxidation of cell wall lipid substances by chromic or periodic acid, and the subsequent release of aldehydes which are then capable of reducing ammoniacal silver salt solutions to metallic silver. The organisms so demonstrated appear uniformly solid. The sensitivity of the method and the ease of examination and recognition of bacilli and their products are recommendations for the use of the method in diagnosis and research, disregarding morphological appearances.