The purpose of this project is to use the results from biochemical tests that you studied in Modules 8 and 9 in order to identify an unknown organism. Please, review all biochemical tests in Modules 8 and 9 (what are they used for, how to record results appropriately, and the interpretation of those results). This is a list of the steps that you will be taking when completing this project:
The first step is to sign-up for your unknown number. In order to do that, you will sign-up for an unique unknown number. To do that, click on Tools, then Groups.
Then, you will complete the Unknown Project Survey Quiz located on Assessments, then Quizzes & Tests. This quiz is not for a grade.
Complete the survey in D2L. Once you have submitted the Unknown Project Survey Quiz, you will see a file in Module 11 folder that is titled “Gram Stain and Morphology Results for Unknown Project”.
Open the “Gram Stain and Morphology Results for Unknown Project” file. You will see three pictures in that file and some numbers underneath those three pictures. The purpose of this file is to find your unknown number and classify it as a Gram-negative rod, Gram-positive coccus, or Gram-positive rod. Use this classification to narrow down the names of the possible organisms of your unknown. To do this you will use another file that is located in Module 11 folder titled “Unknown Table”.
You will be using this table a lot during the project. This table will help you to:
・
Narrow down possible identities of your unknown
Determine which biochemical test you will check for your unknown
Dentity your unknown
Once you have identified your unknown as a Gram-negative rod, Gram-positive coccus, or Gram-positive rod, you will then proceed with the identification process using a variety of biochemical tests. The first test that you will be using is the Phenol Red Sugar Broth (both glucose AND lactose). Once you have viewed the “Gram Stain and Morphology Results for Unknown Project” file in Module 11, another file will be available: “Phenol Red Glucose and Lactose Results for Unknown Project”. This test is mandatory for everyone regardless of your unknown and it must be the FIRST test to run in the identification process.
You will be filling out the Unknown Lab Report file that is on the Assignment tab.
The other file that you see in there is a rubric. It shows how points will be deducted.
Here is an example. Let’s say that I signed up for number 100. According to the Gram stain and morphology, my unknown is a Gram-negative rod. According to the Unknown Table, my unknown may be one of these 9 on the right. When I check the Phenol Red Glucose and Lactose for number 100, I see that for both number 100 is listed under the picture that is yellow with a void volume and under the picture that is yellow without a void volume. These observations mean, that for both phenol red glucose and phenol red lactose the results must be typed as “A/G or A/-“. For glucose, the interpretation would be that the unknown ferments glucose with or without CO, production. For lactose, the interpretation would be that the unknown ferments lactose with or without CO, production. Using the Unknown table, I can conclude that the possible organisms now are “E. coli, K. pneumoniae, K. aerogenes, and even P. vulgaris”. Based on this, I decide that the next test that I want to check on is citrate (see screenshot of table):
This is a screenshot of how my lab report would look like at this point in my quest:
In the Unknown Lab Report, you will see tables for all the biochemical tests that you learned about in Modules 8 and 9. While all tests are listed in the lab report file, you must only report those tests that you ran (or checked) on your unknown.
For each test, you must type the results and the interpretation. For example, if the gelatinase test shows a liquid result, then the results are listed as positive, and the interpretation is “My organism is able to break down gelatin” OR “My organism has gelatinase”. Then, list the possible organism(s), whether or not you have identified it, and which test is next and why. You will do that for every single test that you ran or checked. For tests that look for multiple reactions, such as SIM, you must list all results (S, 1, and M) regardless of whether they helped you to identify your unknown or not. I should be able to track your thought process as you are listing the tests and the rationale of why you chose the next test. Once you have identified your organism, you must do some research as directed on page 7 of Unknown report document. You will have empty tables on your lab report and that is expected. Reporting unnecessary tests will result in loss of points. You CANNOT report every single test on your unknown (that is not how this works!). You must decide which test is good for your unknown. Once you have identified your unknown, you must stop running tests. I will not confirm the
