MLT1 – Lab Report 1 Bacterial Morphology

Nichole

Performed at Home

3/21/13

Bacterial Morphology

A. Comparing Observations from Mounting Techniques

Four mounting techniques were used during this experiment which included the fresh

wet mount, direct staining using crystal violet, and indirect staining using both Congo Red and

crystal violet. There was a liquid appearance in the wet mount slides with the cells

appearing very similar in color to the liquid from the sample. The cells and their borders

in the wet mounts were not as distinct in appearance as in the staining methods. While the

bacteria shapes were able to be identified in the yeast wet mount, it was very difficult to

determine the shapes in the cheek smear. The next method used was the direct staining using

crystal violet. The cells in the direct stained slides were very easy to view, well defined and were

a distinct violet color. The indirect staining method using the Congo Red dye appeared to

actually stain the cells in the cheek smear rather than the background and area around the cell.

In the higher resolution cheek cell slide, the cell was outlined with the Congo Red dye. The yeast

cells were easily identified using the indirect method however the cells in the plaque smear

were not. There was a large area of dye in one area on the slide and did not appear to surround

the cells to help define them and make them easily identifiable. In conclusion of the comparison

of mounting techniques, it appears that direct staining using crystal violet produces the most

clear and defined view of the cells.

B. Bacterial Morphologies

Bacterial morphologies were easier to determine in certain