Lab 4 Blood Analysis
Name __________________________ Date ____________________
Lab Section______________________
To Do Before Lab!
• Complete the lab reading below.
To Do After Lab!
• Keep all the notes and diagrams you create as part of the activities below. Lab practical exams will be composed of a selection of these questions/tasks.
Today’s Materials
• Compound light microscopes • Hematocrit samples
• Prepared microscope slides • Rulers
• Textbook
1.
Activity 1: Pathological Differential White Blood Cell Count
A differential WBC count is performed to determine the percentage of each of the five types of WBCs in a blood sample. When attempting to learn which WBCs are
normally present from the greatest to least percentages, it is helpful to remember the following mnemonic: “Never Let Monkeys Eat Bananas” (N = neutrophils; L =
lymphocytes; M = monocytes; E = eosinophils; and B = basophils). Because the normal percentage of each WBC type is known, any significant abnormality in these
percentages, elevated or depressed, can be indicative of particular disorders. Numerical values for the normal range of WBCs may vary depending on the reference
source.
1. Each lab partner within your lab group will take turns identifying WBCs with the microscope and call out the WBC type to the lab partner tallying the results
as marks (|||| ||).
2. The lab partner tallying the results should help track that each lab partner has identified approximately 25 WBCs to ensure an equal distribution of workload.
The total number of WBCs should be 100.
3. Focus a prepared microscope slide of abnormal blood “Leukocytosis” at 400x TM.
4. To avoid recounting any WBCs, begin at one end of the slide that has a good separation of cells and slowly scan systemically, moving the slide down and over,
then up and over, and repeat as seen in Figure 26.3.
5. If you encounter a cell that you cannot identify or are not sure of, do not count it and continue on.
6. As a group, continue this pattern until you have found and recorded 100 WBCs in Table 26.2.
7. Because you are counting 100 WBCs, the total number of each type of WBC counted is its percentage in the blood sample (i.e., 26 lymphocytes means 26%
of the WBCs are lymphocytes).
8. Write your results on the board to pool class data.
9. Determine the disorder by consulting Table 26.3 below and record in Table 26.2.
Table 26.2 Results of Pathological Differential WBC Count
Type of WBC Photo Observation % of Total Class Average (% Normal % of Type of Disorder
Tally WBCs of Total WBCs) WBCs
_____ x 100% =
100 60-70%
Neutrophil
_____ x 100% =
100 20-25%
Lymphocyte
_____ x 100% =
100 3-8%
Monocyte
_____ x 100% =
100 2-4%
Eosinophil
_____ x 100% =
100 0.5-1%
Basophil
Total WBCs 100 100% N/A N/A N/A
Activity 2: Microscopy Practice
• Demonstrate appropriate recording of microscopic observations at 400x total magnification (TM): include labeling of the following boldface cells or cellular
fragments.
• Your diagram need not be perfect! Make it plenty large so that you can include details. Use color for your sketches if possible. Ask the instructor for assistance
if you’re uncertain about what you’re seeing!
Sickle Cell Anemia at 400x
• Sickled erythrocytes
• Normal erythrocytes
• Platelets (thrombocytes)
Activity 3: Blood Analysis
A hematocrit determines the volume of RBCs described as the presence of RBCs in a whole blood sample. A capillary tube of blood is centrifuged to pack the
red cells at the outer end of the tube, separating them from the WBCs, platelets, and plasma. After measuring the length of the RBC column and the total
length of the blood column, the percentage of RBCs can be calculated. The normal hematocrit range for females is approximately 38 to 46% and for males it
is 40 to 54%. An abnormally high hematocrit (generally 65% or above) is indicative of polycythemia, and a hematocrit with RBCs below the normal level
indicates a type of anemia.
1. Interpret hematocrit values of four samples and indicate whether each is normal or suggests conditions, such as anemia, dehydration, or polycythemia.
• Patient A: __________________________________
• Patient B: __________________________________
• Patient C: __________________________________
• Patient D: __________________________________
2. Calculate the hematocrit for blood in the capillary tubes in Figure 26.4.
• Use a millimeter ruler to measure (in mm) the length of the whole column (the length of packed RBCs, WBCs, and plasma) and record it in
the following table.
• Measure the length (in mm) of the RBCs and record it in the following table.
• Use the following formula to calculate the percentage of RBCs (=hematocrit) in whole blood:
Length of RBCs in mm x 100%
Length of the whole column in mm
• Record the hematocrit results in the following table.
Hematocrit Capillary RBC Column (mm) Whole column (mm) Hematocrit (Percentage of RBCs/Total Blood)
Tubes
Hematocrit a
Hematocrit b
Discussion Questions
• For the hematocrit capillary tube a in Figure 26.4, is the hematocrit normal, low, or high? ______________________________________
o If abnormal, do values indicate anemia or polycythemia? ___________________________________________________________
• For the hematocrit capillary tube b in Figure 26.4, is the hematocrit normal, low, or high? ______________________________________
o If abnormal, do values indicate anemia or polycythemia? ___________________________________________________________
• In a patient who would otherwise have a normal hematocrit, what do you think are temporary factors that could lead to a false hematocrit
result such as polycythemia? ________________________________________________________________________________________
3. Is blood smear #1 diseased or normal blood? ______________________________
• If diseased, which of the following is the most probable diagnosis or condition?
A. Chronic lymphatic (lymphocytic) leukemia
B. Leukocytosis
C. Leukopenia
D. Polycythemia
E. Sickle cell anemia
