Purpose, Procedure and Preparation. Gram stain is probably one of the most commonly used staining procedures used in the field of microbiology. It is one of the differential stains that are used to characterize bacteria in one of two groups: either gram positive bacteria or gram negative bacteria.
In this regard, what does Gram stain tell you?
Gram staining is a common technique used to differentiate two large groups of bacteria based on their different cell wall constituents. The Gram stain procedure distinguishes between Gram positive and Gram negative groups by coloring these cells red or violet.
Why is staining so important?
Stains are classified broadly as basic, acidic, or neutral stains. The chemical nature of the cells under examination determines which stain is selected for use. Cell staining is important in the diagnosis of microorganisms because bacteria can be identified by the color differentiation of stains (dyes).