Identifying an unknown organism Biology Lab Report
Objective: Identification of an unknown organism
You will be assigned an unknown organism that you will identify by performing a series of morphological and biochemical tests. Identification of the unknown organism will require use of the biochemical tests covered in previous labs, differential/selective media covered in lab 4 and Gram-staining
Procedure: Once you have been assigned your unknown,
- Label the TSA plate handed to you by the IA with your full name, date, and lab section. This plate is your stock master plate. You will use the stock plate to create a working plate and to perform a Gram stain in today’s lab
- Working plate: Transfer a single isolated colony from your stock plate to a fresh, sterile TSA plate (labeled with your name and lab section) and streak for isolation. Incubate the plate at 37°C for 24 hr., move the plate to the student (white door) refrigerator after incubation. This is your working plate; all your biochemical tests must be inoculated from this working plate (except catalase test).
- Gram stain: Using another isolated colony from your stock plate, prepare a smear and Gram stain it following the procedure outlined in your manual. Now refrigerate your stock plate as well.
- Record the results of your Gram stain below.
- Plate code ES85
- Gram stain observation:
Morphology Cocci
Gram nature; Positive
- Once your Gram staining results have been confirmed, proceed with the biochemical tests as per the flow chart provided below. There is one flow chart for Gram-positive bacteria and a separate one for Gram-negative bacteria. Make sure you are following the correct flow chart.
- Inoculate your biochemical tests with a single isolated colony from your working plate. You may use your working plate for up to 4 days, you will need to streak a fresh TSA plate if you need to continue performing tests after 4 days. If you make a fresh working plate, discard the old working plate as we have limited space in the refrigerator for storage.
- To make a new working plate, follow the same procedure as described above (step 1a).
- Perform one test at a time. After the test results have been recorded, proceed with the next test as per the flow chart. Do not inoculate multiple tests at the same time; this is a waste of resources and your time. Once incubation is complete, record your observations and discard your test. Any test tubes found in the refrigerator will be promptly discarded. There is more than enough media made for the class to identify their unknowns.
Name Unknown paper grade report
Follow the rubric as you write your paper and attach this page to your report. Submit the paper before the deadline on your lab Canvas site. First draft is due on October 12th, 2022, Late submissions will NOT be accepted.
Section |
Description |
Points obtained |
Gram stain |
Must be graded during the lab, good quality smear (2), correct gram nature (4), correct morphology (4) |
/10 |
Cover page |
Creative and professional title, your name, IA name, lab section, date, unknown #, Genus & species of the identified microbe (correct spelling & scientific format) |
/2 |
Abstract |
1-2 lines summarizing each part of the paper (2)
Include overall results and conclusion (2) |
/4 |
Introduction |
Information on your organism with citations (4)
Information on the tests you used with citations (4) Purpose of this study (2) 1.5 page maximum |
/10 |
Materials and
Methods |
Provide a clear and detailed description of all the tests you would have performed (4) with citations (4). Must be presented in same order as would be performed in the lab
(2). |
/10 |
Results* |
State positive/negative and associated observation arranged in a table (4). A brief narrative summary of the results is appropriate but save the discussion and interpretation for the next section. Credit is given for the arrangement and clarity of the tabular results. Must be presented in same order as would be performed in the lab
(1). |
/5 |
Discussion |
Discuss your results here. Include interpretation of each test (why it was positive/negative) with citations (10). Discuss any problems (or possible problems) encountered (2). Mention the relevance of this experiment (3). |
/15 |
Citations |
Minimum of 4 peer-reviewed citations in the correct format (4).
The manual is not a peer-reviewed publication. Correct citation format: see below |
/4 |
Correct identification |
Correct identification of unknown organism |
/5 |
Total |
|
/65 |
*Refer to the guidelines below for more information on how to write the results section.
Additional guidelines:
- The report should be typed using the following specifications:
Font type: Arial
Font size: 12
Double spaced with 1-inch margins
Past tense, third person
- The materials and methods as well as the discussion section should include a separate header for each of the tests performed.
- Use proper and standard grammar, syntax, and structure. Poorly written and constructed reports will result in a deduction of up to 5 points, especially if your IA cannot even perceive what you are attempting to say. Don’t wait until the last day to write your report.
- Please do not plagiarize. If you are taking this lab for second time (and unless specifically cleared in advance by your IA), you must receive special permission to re-use portions of your own previous paper.
- Results: provide adequate figures for each test you would have performed. You may include pictures of tests for figures (Like a negative Gram stain for a Gram-negative organism). Give only factual details about the observed results; do not discuss the implications or interpretations of the results in this section. Figures of tests must appear in same order as would be performed.
TO USE A TABLE: Include the table legend ABOVE the table, include all tables BEFORE all figures. Reader must be able to interpret your table from your legend alone.
TO USE A FIGURE: Include the figure legend BELOW the figure. Reader must be able to interpret figure from your legend alone.
- Citations: Arrange your references in alphabetical order at the end of the report. Cite each listed reference by a number (in parentheses) in your report text. When compiling the reference list, use the style described below.
Authors. Year. Paper title. Journal. Volume: Pages
Remember that citations are very important; for EVERY SECTION (except for abstract and results), you should include citations in the body of the paper in correct format. You can choose to cite with a number, or with the author’s name and the year. If the article that you are citing has multiple authors, use: (Last name of first author et al. year)
Example citation: (see http://pitt.libguides.com/citationhelp/APA )
In text: “Streak plating is a technique that is used to separate a mixed culture into isolated components (Zhang et al. 2016).”
On citation page:
- Zhang, R. H., Zhou, Z. H., & Feng, J. C. (2016). Isolation, Identification, and Characterization of Lambda-Cyhalothrin Pesticide Degrading Bacterium ZC-5. Key Engineering Materials,723, 628-632.
Ideally you would use more than 4 citations, as every claim you make that is not considered common knowledge needs to be cited (especially in a publication ready manuscript). The lab manual is neither a peer-reviewed publication nor a formal scientific publication, so it should not be cited. Be sure to arrange your references in alphabetical order at the end of the paper for full credit.
Strive to use peer-reviewed papers of formally published scientific journals (even for materials and methods). That means that neither the lab handout nor random websites should be included. You could also find research via Google Scholar or NCBI PubMed if you make sure that the articles you are using are peer reviewed.
Also, once you finish your paper, I highly encourage you to make sure that you followed the rubric before you submit it. The grade is based on this rubric and the quality of your written work. For example, you must use proper grammar and syntax to be sure your paper makes sense.