Lab 6
Blood
Dichotomous Key
Blood Cells
Examining the Formed Elements of Blood Microscopically (Using a prepared slide.)
Differential Count - Modified
Blood Analysis – PhysioEx 8.0. Access in lab, the library, on Canvas or in
Mastering A and P
Activity 1: Hematocrit Determination, 1 - 10
Activity 5: Total Cholesterol Determination, 1 – 10
Note: You must use PhysioEx 8.0 for this lab. Version 9.0 will not work.
If you are using Mastering A&P, you can access version 8.0 in Study
Area (myA&P) at the top right of the screen. You may also use the copy on Canvas,
borrow a disc from me at the front desk or use a copy that is in the library.
Lab 6
Name___________________________
Lab Section _____________
Turn this in at the next laboratory session.
A. Dichotomous Key
Prepare a dichotomous key that separates each blood cell type into a separate category
using the classification of blood cells and the unique characteristics you described in the
pre-lab activity. If you do not know how to construct a key, directions are attached.
Draw a picture of each type of blood cell at the end of the key, using the characteristics
you described in the pre-lab exercise. Color each cell appropriately. Be sure that you
use the correct relative sizes for each cell. Label nucleus and granules if appropriate.
Colored pencils are available in the lab. (26 points)
B. Prepared Slide of Blood Smear
Use a prepared slide of a blood smear and be sure you can identify all the formed
elements on a slide. Use the photos in the text, Figure 19-10, an histology atlas or web
sites, and your dichotomous key to help you identify the cells. Use the 40X lens.
C. Conducting a Differential WBC Count.
Differential White Blood Cell Counts
(Also Called CBC – Complete Blood Count) (Modified from http://www.rnceus.com/)
Normal values for total WBC and differential in adult males and females are:
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Total WBC: 4,500 - 10,000/mm3
Bands (immature neutrophils): 3 - 5 %
Granulocytes (or polymorphonuclears)
o Neutrophils: 50 - 70% relative value (2500-7000 absolute value)
o Eosinophils: 1 - 3% relative value (100-300 absolute value)
o Basophils: 0.4% - 1% relative value (40-100 absolute value)
Agranulocytes
o Lymphocytes: 25 - 35% relative value (1700-3500 absolute value)
o Moncytes: 4 - 6% relative value (200-600 absolute value)
Each differential always adds up to 100%. To make an accurate assessment, consider
both relative and absolute values. For example a relative value of 70% neutrophils may
seem within normal limits; however, if the total WBC is 20,000, the absolute value (70%
x 20,000) would be an abnormally high count of 14,000. The absolute value is the %
of a cell type times the total WBC count.
Leukocytes: critical low and high values
Leukocytosis (high WBC count): a WBC count above 10,000. A WBC count over 30,000
indicates massive infection or a serious disease such as leukemia.
Leukopenia(low WBC count): WBC count falls below 4,000. A WBC count of less than
500 places the patient at risk for a fatal infection.
Procedure
1. You will be given a card with approximately 50 WBCs on it. It will also contain
information about the total WBC count for the sample and other information if
relevant. Count the number of each of the different types of WBCs and fill in the
chart below. Multiply your counts by 2 to find the differential WBC count for
your sample. (The differential count is based on 100 cells and is reported as a %)
2. The two figures below may help you with some unusual blood cell types.
3. Using your data, decide which of the following eight scenarios is the most likely
explanation for your results.
Band Neutrophil
Ragged or Atypical Lymphocyte
Scenarios
1. This patient has AIDS. His lymphocyte count is low, which makes the
percentages of other WBCs seem high because the total WBC count is in the
normal range.
2. This patient has acute appendicitis, caused by a bacterial infection. Her total
WBC count is high and her neutrophil count is high as well. There is a higher
than normal percentage of “bands” in the sample.
3. This patient has viral mononucleosis. Her lymphocyte count is high as
lymphocytes enter her blood to fight the viral particles. The lymphocytes look
a bit atypical with ragged edges.
4. This patient just returned from the tropics and has picked up a filarial
(roundworm) infection. His eosinophil count is high as the eosinophils
attempt to fight off the parasite infection.
5. This patient has acute myeloid leukemia. Red blood cell and platelet levels
are low as are the WBC levels. This patient is tired, achy and bruises easily.
6. This patient has swollen lymph nodes and a high lymphocyte count. He is
suffering from B-cell chronic lymphocytic leukemia (B-cell CLL).
7. This patient is feels tired, is gaining weight, is very sensitive to the cold and
has an elevated basophil count. She has been diagnosed with hypothyroidism.
8. This patient has tuberculosis which, among other things, has resulted in a
condition called monocytic leukocytosis or monocytosis.
Cells
Segmented
neutrophils
Band neutrophils
Tally
Total
Lymphocytes
Monocytes
Eosinophils
Basophils
Total cells counted
___________
What is your patient’s total WBC count? (This is on the card.) ____________________
Is this normal, high or low? ____________________
What is the % of each of the cell types in the sample? This is the tally x2 if there are 100
cells. In some cases there are a few more that 100 cells. Just multiply the count by 2 as it
will not make a major difference. This number represents the % of each blood cell type.
Record in the table below.
What is the absolute value of each of the cell types you counted? This is the % of each
cell type x the total number of cells. Record in the table below.
Normal Counts
Segmented
Neutrophils 50-70%
Band Neutrophils 05%
Lymphocytes 2540%
Monocytes 3-8%
Eosinohils 2-4%
Basophils 0-1%
Your
Patient’s
WBC Type
Count (%)
(Tally X 2)
Your Patient’s
Absolute
Count
Evaluation
High, Low,
Normal
Compare your counts with the normal percentages and diagnose your patient’s condition.
Your counts are percentages because they are based on 100 WBCs.
Put the letter of your patient here ________
What is your diagnosis and why?
________________________________________________________________________
________________________________________________________________________
_______________________________________________________________________
D. Blood Typing ( modified)
(From Ward's or Carolina’s Simulated ABO and Rh Blood Typing)
Blood typing is an example of an antigen-antibody reaction. Antibodies are a normal part
of the immune response. In this example, the antigen-antibody complex that forms is a
clump of blood cells.
A. Refer to your text, page 671, or the lab manual, pages 433-435 for information about
ABO and Rh blood groups and blood typing.
B. Obtain a blood typing kit for your lab group. The kit should contain:
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1 vial of simulated Anti-A Typing Serum
1 vial of simulated Anti-B Typing Serum
1 vial of simulated Anti-Rh Typing Serum
4 vial of blood samples
1 blood typing tray
toothpicks
glass marking pencil
C. Using the wax marking pencil, label each blood typing slide with the number of the
sample to be tested (1, 2, 3, 4).
D. Follow directions for the
Ward’s
Carolina kit. (Circle one)
Carolina:
Place one drop of simulated blood in each well of the typing slide.
Add one drop of anti-A serum in each A well
Add one drop of anti-B serum in each B well
Add one drop of anti-Rh serum in each Rh well
Stir each well with a different clean toothpick. Avoid cross contamination.
Wait a few minutes and observe each well.
Record observations on the data sheet, and answer the related questions.
Ward’s:
Place three or four drops of simulated blood in each well of the typing slide.
Add three or four drops of anti-A serum in each A well
Add three or four drops of anti-B serum in each B well
Add three or four drops of anti-Rh serum in each Rh well
Stir each well with a different clean toothpick. Avoid cross contamination.
Wait a few minutes and observe each well.
Record observations on the data sheet, and answer the related questions.
Blood Typing Results
A. Record your clumping (agglutination) observations below:
use + to indicate clumping
use - to indicate no clumping
Sample #
Anti-A
Anti-B
Anti-Rh
Serum
Serum
Serum
Blood Type
1
2
3
4
B. Questions (Check your results with me before proceeding with the questions.)
Answer these questions at home after you have completed the lab. They will be
useful in preparing the poster for a poster session next week.
1. Give a general definition of antigen.
2. Give a general definition of antibody.
3. What ABO and Rh antigens are present on the surface of each sample of blood?
Sample #
Blood Type
ABO
antigens
A, B
Rh antigens
( + or - )
1
2
3
4
4. For several possible reasons, blood serum contains antibodies to ABO antigens NOT
present on the red blood cells in that blood. (The same is not immediately true for Rh
antigens.) What ABO antibodies are in the serum of these blood samples?
Sample #
Blood Type
ABO
antibodies in
the serum
A, B
1
2
3
4
5. If any of these people needed a transfusion, what ABO blood type(s) could be used?
Sample #
Blood Type
ABO Blood Types
for transfusions
1
2
3
4
6. What happens to erythrocytes if incompatible ABO blood types are mixed?
7. Which of the people should not be given Rh+ blood? _________________
Why not?
8. Answer the following questions based on the results from Sample 3.
What is the ABO and Rh genotype of this person? ABO________ Rh _________
phenotype? ___________
Can a man with Type O blood be the father of this person? _______
Illustrate your answer using a Punnett Square – ABO blood groups only.
Can this person have one parent with Type A blood and one with Type B blood? _____
Illustrate your answer with one example on the Punnett Square – ABO blood groups
only.
Explain why Sample 3 cannot be the parent of a Type O child.
Sample 3 has parents who are both Rh+. How is this possible?
E. Total Cholesterol Determination
Activity 1: Hematocrit Determination, 1 - 10
Activity 5: Total Cholesterol Determination, 1 - 10
Activity 1: Hematocrit Determination. Follow directions in the lab manual or from
the handout at the front desk.
1. Record Data in the Table below:
Blood Sample
Height of
Column of
Blood
(mm)
Height of
Red Blood
Cell Layer
(mm)
Height of
Buffy Coat
(WBCs)
(mm)
Hematocrit
%WBC
Healthy male
Boston
Healthy female
Boston
Healthy male
Denver
Healthy female
Denver
Male aplastic
anemia
Female iron
deficiency
anemia
2. What is the hematocrit of a healthy male living at sea level in Boston? _______
3. What is the hematocrit of a healthy female living at sea level in Boston? ______
4. What is the hematocrit of a healthy male living at 1-mile elevation in Denver? ______
5. How can you explain the difference between the hematocrits of the healthy male in
Boston and the healthy male in Denver? Hint: look up the relationship of altitude to
barometric pressure. Air with lower barometric pressure contains less oxygen.
6. What kidney hormone is released in response to low O2 levels? _________________
What is its target tissue? ______________________
What is its function?
Activity 5: Total Cholesterol Determination
Record Data in the Table Below Note: dL refers to deciliter (0.1 liter or 100 ml)
Patient
Approx. Total
Cholesterol mg/dL
Cholesterol Level
1
2
3
4
1. What are some essential roles for cholesterol in the body?
2. What risks are associated with low blood cholesterol?
3. What health problems might be in store for patient 2 based on these results?
4. What advice about diet and exercise would you give patient
Preparing a Dichotomous Key
A dichotomous key is an easy way to sort things out based on a simple set of yes and
no questions. Biologists use keys like this frequently so it is helpful to know how
they work. In this case we are going to construct the key first, and then use it.
Imagine that you have just selected the Jack of Diamonds from a deck of cards and
you want your friends to guess what card you selected. Since you want them to
guess in a logical way, you tell them that they can only ask questions with the
answer “yes “or the answer “no”. There are many ways to do this correctly. Here is
one example.
·
·
·
·
·
·
Is the card red? Yes (This eliminates all the black cards in the deck.)
Is the card a heart? No (This eliminates the hearts, so the card must be a
diamond – no other choices!)
Is the card a face card? Yes (This eliminates cards 2 through 10)
Is the face card a male? Yes (This eliminates the queen.)
Is the card the King? No
This eliminates the King, so the card must be a Jack of Diamonds. (Red, not
heart, male face card, not the King!)
Set up the questions like a branching tree or flow chart.
Y
N
?
?
Y
?
N
Y
N
For the Lab Exam
Identify on slides or pictures:
o basophil
o eosinophil
o erythrocyte
o lymphocyte
o monocytes
o neutrophils
Give observable characteristics of red and white blood cells.
Interpret results of blood typing.
Interpret hematocrits
Interpret results of cholesterol testing