hnique learned in the first lab was applied to cover the slide with nigrosin solution. A sketch was then made. Gram staining was more complicated. First, two separate types of bacteria were used. One type was placed on one slide, and the other bacteria were placed on the opposite side. Both bacteria were also placed in the middle of the slide so they could be viewed together. Crystal violet, iodine and safranin were all placed on the slide and washed off with distilled water. Once dried, oil was applied to the slide, and it was ready to be viewed. Again a sketch was made.ResultsThe sketches were drawn on a separate piece of paper and then revised. A table is provided.E.coliB. subtilisS. marcesansS. megaturiunSizeSmall, rod-shapedSmall, rod-shapedRound, very smallRound, small clumpsElevationConvexFlatConvexConvexSurfaceShinyRoughRed, smoothSmoothColorWhite, shinyPale yellowReddish-orangeLight purpleEdgeWrinkledRoundRoundRoundDiscussionThe basic purpose of this lab exercise was to view the different characteristics of certain types of bacteria. Using the oil immersion lens accomplished this task. The importance of the lens is that it can get so close to the slide (it is basically touching it) and gives the experimenter a great view of the desired object. The different staining techniques were very useful. The simple stain just stains the cells, so the basic shape of the cell is viewed. With the negative stain, the background is stained, so the elevation, color, and surface are more easily observed. The gram stain, dyed the bacteria either red or purple by using the iodine, methylene blue, crystal violet, and safranin, helped determine the difference between the gram negative or gram-positive bacteria. If the gram stain is negative it will have a lipopolysaccharide cell wall, if positive, it is a peptidoglycan cell wall. Once this is known, scientists can engineer antibiotics that disrupt the bacterias process of protein sy...
