Place a small inoculum of the microbes onto a glass slide. Use a sterile loop to do this so you do not contaminate the slide.
Use a squeeze bottle or dropper to pour a small amount of crystal violet dye over the specimen. Let the dye remain on the specimen for 20 to 60 seconds. Rinse the slide with distilled water for approximately five seconds.
Use a second squeeze bottle or dropper to pour a small amount of Gram's iodine over the specimen. Let the iodine remain on the specimen for 20 to 60 seconds. Rinse the slide with distilled water for approximately five seconds.
Rinse the slide with acetone or ethanol for only as long as it takes to remove the puddle of purple dye from the slide. Stop adding acetone or ethanol as soon as a drop of it runs clear off of the slide, as opposed to purple.
Pour safranin or another counterstain over the slide. Let the dye remain on the specimen for 20 to 60 seconds. Rinse the slide with distilled water for approximately five seconds.
Place a coverslip over the specimen. Put the slide on the viewing platform of a microscope.
Adjust the focus of the microscope so you can see the specimens clearly. Identify them as Gram-positive or Gram-negative (purple or red, respectively).