Gram stain technique

Welcome to our suite of NUI Galway Microbiology teaching videos. We hope that they will guide you in performing your experiments in a scientific and safe manner. This video describes how to perform the most widely used differential staining technique in microbiology: the Gram stain. Developed by Dr Christian Gram in 1884, it categorises bacteria as Gram positive or Gram negative. In addition, this stain also allows determination of cell morphology, size, and arrangement. It is typically the first differential test performed in bacterial identification.