A modified allochrome procedure for demonstrating mycobacteria in tissue sections.

A modified allochrome staining procedure is presented as being the most reliable and sensitive method for demonstrating mycobacteria in tissue sections. The technic is as follows: Deparaffinize formalin fixed sections, oxidize in 10% periodic acid for 24 hours, differentiate in 1% HCl-70% ethanol, stain in Weigert's iron hematoxylin nuclear stain, and counterstain in picro-methyl glue. Mycobacteria stained brilliant red in contrast with the allochrome-stained background tissues, and apparently otherwise chromophobic bacilli are demonstrated.