Microbiology is the biological study of organisms too small to be seen with the naked eye (1). Microbiology involves the examination of a variety of different microbes such as bacteria, archaea, protozoa, fungi, and viruses (1). By examining these microbes, we better understand their relationship with humans and the environment in which they thrive. These examinations of microbes have played a major role in understanding how microbes can be helpful and harmful, and how best to treat them. With new and emerging discoveries in microbiology, medical treatments have expanded. By integrating the understanding of microbes into the field of medicine, it will be possible to better develop the search for cures to combat dangerous diseases, such as HIV. MicrobiologistBased on the Gram reaction, the tests I chose to do were Oxidase, Sulfur Reduction, Indole Production, Motility (SIM), Citrate Utilization, Urease and methyl red and Voges-Proskauer (MRVP). Microscopic examination: Cell morphology is an important characteristic that helps identify bacteria. The three main forms of bacterial cells are cocci, bacillus, and spirilla (3). Dyes were used to facilitate the observation of bacterial cells under a microscope. A Gram stain is a type of differential stain that determines whether a cell is Gram-positive or Gram-negative. “The size, morphology and arrangement of bacteria can also be determined using this staining” (2). The negative charge of bacterial cells attracts the positive charge of the dyes used, thereby causing the cell to color (2). The Gram stain performed on unknown #53 did not retain the crystal violet once decolorized. The unknown bacteria adhered better to the Safranin stain and appeared to be a pink-colored bacteria under the microscope. This indicated that the unknown bacteria was Gram negative. Microscopic examination of the unknown bacteria also indicated that it was shaped like a bacillus (stick). The positive control used for microscopic examination was Escherichi coli and the negative control was Staphylococcus aureus. CatalaseThe Catalase test indicated a positive result. This showed that the bacteria contained the enzyme catalase which converts hydrogen peroxide into water and oxygen gas. The positive control used for this test was Micrococcus and the negative control for this test was Entercoccus. The results of the sulfur reduction, indole production and motility (SIM) test indicated that the bacteria lacked the enzymes cysteine ​​reductase or thiosulfate reductase and were therefore unable to reduce sulfur. The positive control used for sulfur reduction was Proteus mirabilis and the negative control used was Staphylococcus epidermidis. The results of this test were most similar to those of the negative control. The SIM test also indicated a positive result for indole production and motility. This indicates that the unknown can produce indole due to the presence of the enzyme tryptophanase and is also capable of motility. The positive control for indole production was Escherichi coli and the negative control used was Enterobacter aerogenes. The positive control used for motility was Proteus mirabilis and the negative control was Staphylococcus epidermidis. The bacteria SIM results most closely resembled the positive controls. The citrate test on the bacteria indicated a negative result. This indicates that the bacteria does not