The sample is smeared on to a microscope slide and transported back to the laboratory. The bacteria take up the stain through tiny holes in their wall known as pores. Certain types of bacteria have large pores, others have only small pores The excess Crystal Violet is rinsed off of the slide and then iodine is added. The smaller pores are closed completely, the larger pores only partially The slide is decolorized with a chemical that removes all the Crystal Violet from the bacteria whose pores are only partially closed. A pink dye called Safranine is added to the slide for 30 seconds, then rinsed off.
Bacteria occur in several shapes.
All cocci are Gram positive bacteria. These include Streptococcus sp. And Staphylococcus sp. which make up the majority of the normal bacteria flora seen in healthy psittacine birds. Examples include E. coli, Pseudomonas, Proteus, Citerbacter and Enterbacter sp. Spirochetes are also Gram negative.