Cover Page
Project 1
Introduction to Microbiology Laboratory
Photomicroscopy, Leukocytes & the Wright Stain
Author:
Due Date:
Lab Day & Time:
Portions of these materials are adapted from the Microbiology Laboratory Manual by Cynthia Schauer. For additional materials that correspond to this
lab project, see the Virtual Microbiology Classroom 16-week class of the Science Prof Online website.
Introduction
Summarize your reading and provide a purpose for performing the exercise. The readings are the
assigned readings for each lab, your textbook and appropriate lecture notes. You may consider using the
following outline to help you compose your introduction:
I.
The purpose of the exercise to allow me to understand the expectations of the microbiology
laboratory.
A. My understanding of the attendance policy is___________; this policy is important because
___________.
B. For every laboratory session I am expected to ________________;
each of these
components is important because ____________.
C. Lab reports will be written____________
D. My progress for the lab will be determined by___________
E. The rules for the laboratory can be summarized by _____________; they are important
because___________;
i. It is expected that I will adhere to lab rules_______________
ii. The consequences for lapses in adhering to lab rules is ___________
II. The purpose of the laboratory is to properly use the microscope and the digital camera attached to
the scope.
Provide a summary of how you will use the scope and explain why the proper use of the
equipment is important.
Hypothesis
Here is where the purpose of the lab is summarized in the hypothesis statement. The question(s) to be answered
during the lab is (are) clearly identified and stated using an ‘if…then’ statement(s).
If I know and understand the rules of the laboratory then __________________________.
If I observe human blood cells stained with Wright’s stain then I will be able to recognize neutrophils
because ________________.
Materials and Methods
Provide an overview of your procedure. Procedures are to be listed in clear steps. Each step is numbered and
expressed a complete sentence. Methods are written in the past tense. Remember, you may not copy and paste
from the lab handout---that would be considered plagiarism. In all future labs, your lab outline will be
sufficient for the material and methods section.
Results
Provide a narrative of your results in one or more paragraphs. Results are presented in diagrams, photos,
tables and/or graphs which are referred to in your narrative. Your tables and/or graphs should be a
professional looking and accurate representation of the data. Include clear, accurate diagrams are and
make the experiment easier to understand. All diagram /drawings, photos, tables and graphs are titled
and labeled neatly and accurately.
We observed a human blood smear stained with Wright’s stain and took photographs of a neutrophil and a
lymphocyte. The neutrophil is larger than the numerous red blood cells that surround it. It is
characterized by a dense purple staining nucleus and lighter pink/purple staining cytoplasm. The nucleus
has different shapes in different neutrophils. It was approximately 13 µm in width. (See Figure 1)
Repeat a similar description for the lymphocyte you observed.
Remember, all data presented in the lab report should be properly labeled (i.e. Figure 1), titled (Wright’s
Stain of Human Blood), and the total magnification should accompany it. You should label as many
aspects of the pictures you use (i.e. nucleus, cytoplasm) to show your knowledge of the subject.
Portions of these materials are adapted from the Microbiology Laboratory Manual by Cynthia Schauer. For additional materials that correspond to this
lab project, see the Virtual Microbiology Classroom 16-week class of the Science Prof Online website.
Neutrophil
Figure 1: Wright’s Stain of Human
Blood; Total Magnification 400
X)
Analysis
Analyze the results relative to your hypothesis.
1. Explain the effect Wright’s stain has on blood cells.
2. Describe how you would distinguish between neutrophils and lymphocytes.
3. Refer back to your hypothesis regarding the identification of the white blood cells (neutrophils and
lymphocytes).
Comment on whether or not your hypothesis is supported by your results.
(Remember: you can never prove a hypothesis---only support it or not)
Conclusion
Describe how the results answer the question (or not). Summary describes the skills learned, the
information learned and some future applications to real life situations. Experimental errors, their
possible effects, and ways to reduce errors are discussed.
1. Refer back to your hypothesis regarding the identification of the white blood cells (neutrophils and
lymphocytes). If your hypothesis was supported, think of some ways this information may be
useful to you in the future (i.e. what did you learn and how will you apply it in the future). If your
hypothesis was not supported, try to figure out what happened---perhaps propose some other way
to approach the problem.
2. Make a statement regarding the validity of your results. (How likely is it that all neutrophils will
look like this? Did you see neutrophils from other sources? Will they always look like this? Will
you be able recognize them again? )
3. Identify potential sources of error.
a. Were there some things you learned in this lab that you might do differently should you
perform the technique again---for instance, I wish I had taken the picture in the example in
an area of the slide where the RBC’s were more spread out---I think the neutrophil would
look more characteristic.
b. How could you discern cells from artifact? Why would this be important
Works Cited
See Citing References for Scientific Research Papers.
Portions of these materials are adapted from the Microbiology Laboratory Manual by Cynthia Schauer. For additional materials that correspond to this
lab project, see the Virtual Microbiology Classroom 16-week class of the Science Prof Online website.