Microbiology, including colony counting and Gram staining, is used to evaluate microbial presence, identify bacterial species, and track microbial behavior across various settings, including pharmaceutical, food, environmental, and research applications. Together, these methods provide insights into both the quantity and type of bacteria within a sample.
Colony counting in microbiology relies on the principle that each viable microbe gives rise to a visible colony when incubated on solid media. These colonies differ in shape, size, and density—features that help assess microbial growth, contamination, and consistency.
Gram staining complements this by identifying bacterial cell wall types. Through a sequence of staining steps—crystal violet, iodine, and safranin—bacteria are visually classified under a microscope as Gram-positive (purple) or Gram-negative (pink), offering a clear distinction between types present in the same sample.
