Now, let's move on to the Gram negative bacteria. So the main difference between Gram positive and Gram negative is the thickness of our cell wall of that Peptidoglycan layer. So these bacterial cells are characterized by a thin Peptidoglycan cell wall. Now, because the cell wall is so thin, when we actually stain our bacterial cells with our purple dye, because the layer is so thin, that purple dye can easily wash out when we wash it with water. So that means under the microscope, all that purple dye will be removed after washing and our bacterial cell will appear pink under the microscope. Now, on top of having a thin Peptidoglycan layer, the other difference between Gram negative and Gram positive is that in Gram negative, we also have a second phospholipid body layer found right outside our peptidogly cancell wall.