Lindsay Wootton
Clinical Microbiology Laboratory 211.2
Task 1 A. This experiment consists of four different activities. They include the fresh wet mount, direct staining using crystal violet and indirect staining using both Congo red, and crystal violet. A close examination of these examples showed that the wet mount slide examples were all the same in appearance. the cheek and yeast both appear to have some circular cells. the cheek smear was the most difficult to see. The direct staining images were very easy to make out the cells, as they turned the color of the crystal violet. The indirect staining, also known as the negative staining, used the Congo red dye and produced interesting results. The cheek smear looked like the cells were stained, rather than the background as it was explained in the experiment. It shows in the up close cheek smear, as the yeast smear didn't seem to retain the red color. It was however easier to make out the shapes of the cells. The plaque smear, retained some of the red dye but not in any sort of pattern in which to clearly be able to see cells. B. The bacterial morphologies, also known as the shape of the cells, were very easy to see with the crystal violet stain. The slides showed cocci and bacillus shaped cells. On the wet mount cheek smears it was hard to make out any shapes, but in the direct staining slides you could make out cocci shapes on the cheek and yeast smears. You could also make out some cocci on the indirectly stained yeast slide. C. Direct staining uses dyes that stain the cells, such as the crystal violet, methylene blue, or basic fuchsin. They are considered a basic dye that are used for the direct stains that only colors the cytoplasm of the cell and leaves the background clear. This happens because the cell membrane is negatively charged and the dye is positively charged. The indirect staining uses a dye that is considered to be more acidic. Example of this include Congo red, India ink, or nigrosin. The more acidic dyes have a negative charge which is why the background gets "stained." Sometimes I think it doesn't always work that way. For example, on the cheek smear slide which used indirect staining, the cells appeared to be stained, but not the background. The yeast smears followed this same staining method. The colors for the plaque slide helped me to see the morphology better. D. The plaque and yeast smears showed both differences and similarities between the cells. The direct staining brought out the best detail. I think the yeast smears showed the clearest detail. They included well defined cocci that were all grouped together. On the other hand the plaque smears also showed cocci, but seemed were more scattered, not grouped like the yeast. The yeast cells seem bigger that the plaque. this could be caused because of the fact that yeast expands when it is activated. The plaque also seem to have a few bacillus type cells, unlike the yeast and the bacillus cells seem independent of each other. E. When looking at the cheek smear, the magnification of the smear made a lot of difference as to what you were able to see. Though they all seemed roundish and independent of each other, there appeared to be clustering of the cells. These cells seemed bigger overall. I think this was caused by how these might spread to protect the cheek walls. The edges are also not as well defined as the yeast smears and it reminds me of when you crack open an egg. When opened it spreads and doesn't maintain any specific shapes.