Review of Pathogenic Microbiology

Abstract

The Gram stain aids in the identification of bacteria according to their size, shape and grouping by rendering them more visible. It also helps identify them by dividing the eubacteria into Gram positive or negative organisms. The cell wall composition of Gram negative bacteria differs from that of Gram positive. Since Gram negative bacteria have a high lipid content of their cell walls, one theory holds that the decolorizer (acetone or ethanol) solubilizes the cell wall thus reaching the crystal violet. In the cell wall of Gram positive organisms, the decolorizer is unable to act as a solvent thus the crystal violet remains.