Once dry the microorganisms can be seen under a microscope. This procedure is very different from that of a differential stain. A common differential stain and the one used in this lab is the gram stain which is more complicated the simple stain and uses more than one dye. The procedure involves a primary stain, a mordant that locks in the stain, a decolorizer, and a counter stain. The use of multiple dyes allows the viewer to identify gram negative and gram positive bacteria based on whether it’s pink or purple, respectively. This occurs because of the chemical differences in these two types of bacteria; gram negative bacteria has a thin layer of peptidoglycan in the cellular membrane and an outer membrane and the gram positive bacteria has a thick layer of peptidoglycan in the cellular membrane and lacks an outer …show more content…
With the first stain performed, once the staining process was complete and under the microscope, the E. coli was stained pink which means it is a gram negative bacteria. It was, however a very dark pink color, it also was rod shaped and clustered together very closely. In the second stain performed, the bacteria was very spread out and difficult to see as there were very little colonies. The color of the stain was also indeterminable. Both pictures of the slides were taken at 40x