Answer:
See the answer below
Explanation:
<em>The discovery of Gram staining has revolutionized how microbes, especially bacteria, are classified. Bacteria that are positive for Gram staining are classified as Gram-positive while those that are negative to the procedure are termed Gram-negative.</em>
What constitutes positivity or negativity to the Gram staining procedure is the ability of the cell walls of bacteria to either retain a dye or allow it to be washed off during the procedure. The components of the cell wall differentiate Gram-positive bacteria from the Gram-negative ones and confer the ability to retain dye on the former. Gram-positive bacteria have thick peptidoglycan cell walls and lower lipid contents as compared to the Gram-negative bacteria and with this, they are able to retain the color of the stain used during the Gram staining procedure.
During the Gram staining, a scoop of the bacterial isolate is usually smeared and heat-fixed to a glass slide. Thereafter, crystal violet drops are added to the slide, poured off, and then rinsed with water. A few drops of iodine are then added and allowed to stay for a few seconds before being poured off and rinsed. A decolorizer (an alcohol) is then added to the slide, allowed to stay for a few seconds before it is washed off. The addition of a counterstain follows and the slide is allowed to stay for another few seconds before the stain is washed off. The slide is then rid of water and then viewed under the microscope. <u>A Gram-positive bacterium will able to retain the color of the dye which is purple</u> while a <u>negative bacterium will lose the color of the dye and appear red under the microscope</u>.
