The Gram Stain

The Gram stain is a laboratory technique used to classify bacteria based on their cell wall properties. In this process, bacteria are treated with a series of stains. If the bacteria retain a violet dye after rinsing, they are termed "Gram-positive," indicating a thick cell wall. If they lose this dye and take up a red counter-stain, they are "Gram-negative," which suggests a thinner cell wall. This classification helps in identifying bacterial types and guiding effective treatment options for infections, as Gram-positive and Gram-negative bacteria often respond differently to antibiotics.