Gram Staining Lab Report

In experiment three, Gram staining was used to characterize bacteria, either gram positive or gram negative. The Bacillus slide was Gram positive for the results displaying that it had a strong affinity for crystal violet on applying the iodine. The Bacillus slide stained the color of violet because the thicker and richer the layer of the peptidoglycan walls, the more retention of the stain. While the Pseudomonas slide stained the color of red. The Pseudomonas slide was Gram negative due to the lack and thinness of peptidoglycan, and the second plasma membrane that covers the cell wall. The second membrane blocks the stain’s access, therefore results in Gram negative. A possible error that could have shifted the results is how much stain was

All four of the plates were similar, but they all had different number of colonies that were formed. The no NaCl plates had more colonies, and showed more vast appearances than the 6% NaCl. This results could have been because there was only one condition factor, while 6% NaCl had two condition factors. For overall pigmentation, all plates displayed no pigmentation of either being cream, or tan. The optical properties were mostly translucent, because in some areas they were a few substances of light passing through, because when the plate is lifted towards the light, some light is able to pass through. The appearances and texture of the colonies were dull and smooth. This was due to that the elevation was not as elevated, except for plate four. Plate four was the only one that had the most different appearances. This result could have been because there was no added NaCl and the temperature was at a high of 45oC or 113oF. Bacteria grows best above 40oC, due to an increase of molecular movement. A possible error that of the results is the misreading of the observations. For example, viewing the elevation can be tricky because how high is it is based on one’s perspective. The error of observation is merely based on one’s viewing, so that could have affected bacterial diversity in the soil