Introduction
The Gram stain is a valuable tool to microbiologists in identifying the cell well composition of prokaryotic species. The underlying process revolves around a series of chemical dyes, and their propensity to bind to peptidoglycan polymers in the cell wall. The results allow scientists to infer properties about the outer coating of an organism and is often the first step in identifying an unknown species. For the purpose of our experiment, the results of the Gram stain will be as follows: Gram positive (G+), where the first dye was able to bind within the cell and hold throughout the process, or Gram negative (G-), where the first dye is not able to bind and the second dye is observed.
Some known Gram-positive genera are Bacillus, …show more content…
Within a medical setting, a biopsy can be performed and analyzed rapidly without relying on the growth of bacterial cultures. In part one of this experiment, our skills and reagents were tested by following our Gram stain procedure on known species of bacteria. The species tested were Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, and Moraxella catarrhalis. The second part of our experiment focused on identifying the Gram staining characteristics of an unknown species. Two control groups of positive and negative were used to make comparisons with the unknown …show more content…
95% ethanol is used as the decolorizing agent, which will wash the crystal violet from Gram-negative bacteria, and a final counterstain to stain bacteria that are no longer stained as a result of the decolorization with ethanol. In our case, the counterstain is basic fuschin, a pink dye. Following this procedure, the Gram-positive bacteria should remain purple and the Gram-negative bacteria should be the pink color of the counterstain. The staining procedure is visualized in Figure 1.1 below.
Figure 1.1
Part 1 involved the preparation of a slide containing the above bacterial species, E. coli, B. subtilis, S. epidermidis, and M. catarrhalis. A backup slide was prepared in case a proper stain was not achieved, but was not used.
Part 2 involved the preparation of a Gram-positive species, a Gram-negative species, and Unknown #2, which was chosen at random.
The procedure has been adapted from “G. William Claus, Understanding Microbes, Ch. 7; pages
The Gram stain is a valuable tool to microbiologists in identifying the cell well composition of prokaryotic species. The underlying process revolves around a series of chemical dyes, and their propensity to bind to peptidoglycan polymers in the cell wall. The results allow scientists to infer properties about the outer coating of an organism and is often the first step in identifying an unknown species. For the purpose of our experiment, the results of the Gram stain will be as follows: Gram positive (G+), where the first dye was able to bind within the cell and hold throughout the process, or Gram negative (G-), where the first dye is not able to bind and the second dye is observed.
Some known Gram-positive genera are Bacillus, …show more content…
Within a medical setting, a biopsy can be performed and analyzed rapidly without relying on the growth of bacterial cultures. In part one of this experiment, our skills and reagents were tested by following our Gram stain procedure on known species of bacteria. The species tested were Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, and Moraxella catarrhalis. The second part of our experiment focused on identifying the Gram staining characteristics of an unknown species. Two control groups of positive and negative were used to make comparisons with the unknown …show more content…
95% ethanol is used as the decolorizing agent, which will wash the crystal violet from Gram-negative bacteria, and a final counterstain to stain bacteria that are no longer stained as a result of the decolorization with ethanol. In our case, the counterstain is basic fuschin, a pink dye. Following this procedure, the Gram-positive bacteria should remain purple and the Gram-negative bacteria should be the pink color of the counterstain. The staining procedure is visualized in Figure 1.1 below.
Figure 1.1
Part 1 involved the preparation of a slide containing the above bacterial species, E. coli, B. subtilis, S. epidermidis, and M. catarrhalis. A backup slide was prepared in case a proper stain was not achieved, but was not used.
Part 2 involved the preparation of a Gram-positive species, a Gram-negative species, and Unknown #2, which was chosen at random.
The procedure has been adapted from “G. William Claus, Understanding Microbes, Ch. 7; pages