The procedure involves several steps: 1. Sample Preparation: A sample, such as blood, cerebrospinal fluid (CSF), or a throat swab, is collected. 2. Staining Process: The sample is applied to a microscope slide and stained with crystal violet, followed by iodine, which helps the dye bind to the bacterial cell wall. 3. Decolorization: The slide is then washed with alcohol or acetone. Gram-positive bacteria retain the crystal violet stain, while Gram-negative bacteria do not. 4. Counterstaining: A counterstain, usually safranin, is applied. This stains the Gram-negative bacteria, which appear pink under the microscope, whereas Gram-positive bacteria appear purple.
