Unknown Bacteria Lab Report #21

In Microbiology Lab, we learn the scientific method of streaking, staining, microscopy, aseptic culture, and selective and differential tests. These tests will help me identify my Unknown Bacteria. The first procedure I did was the isolation streak of my unknown out on a Trypticase Soy Agar. The purpose of Trypticase Soy Agar is to provide enough nutrients of the microorganism to grow. After I finish my isolation streak, my plate were incubated and grown. Once I got my plate to look at my results and I realize I started my streaking pattern wrong. Because of the way I started my streaking pattern I wasn’t able to see my own results. However, I did my own research of how my plate should have look like if I had did my streaking right. With an educated guess of my unknown species, the results I found for the plate have colonies agar that are tan- pigment, convex, circular, and smooth. The cells are also motile rods. The colonies can be observed under Ultraviolet Light. The second procedure was to perform a Gram stain. The purpose of the Gram stained method is to differentiate between a Gram positive and Gram negative organisms and also learning about the cellular morphology and arrangements. I carefully prepare a slide smear on three slides and then started the Gram stain procedure. Once the procedure was done, all three of my slides had a pink stain which automatically figured that my unknown bacteria was Gram negative. Then I examine the finished slide under a microscope. When I got the microscope fully focused, I observed my unknown bacteria was Gram negative. The Gram stain results determined my unknown bacteria to be bacillus and spread out in singles under the microscope. For the third procedure, I had to choose three selective and differential growth media to determine my unknown bacteria. My first choice was the MacConkey