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ASCP MLS Hematology Exam 2025 Graded A+
Insufficient centrifugation will result in:
A. A false increase in hematocrit (Hct) value
B. A false decrease in Hct value
C. No effect on Hct value
D. All of these options, depending on the patient -Correct Answer ✔A. Insufficient
centrifugation does not pack down the
red blood cells; therefore, the Hct, which is the
volume of packed cells, will increase.
Variation in red cell size observed on the peripheral smear is described as:
A. Anisocytosis
B. Hypochromia
C. Poikilocytosis
D. Pleocytosis -Correct Answer ✔A. A mature erythrocyte is approximately 7-8
μm in
diameter. Variation in normal size is denoted by the
term anisocytosis. Hypochromia is a term that indicates increased central pallor in
erythrocytes, and poikilocytosis denotes variation in red cell shape.
Which of the following is the preferable site for bone marrow aspiration and
biopsy in an adult?
A. Iliac crest
B. Sternum
C. Tibia
D. Spinous processes of a vertebra -Correct Answer ✔A. The iliac crest is the most
frequently used site for
bone marrow aspiration and biopsy. This site is the
safest and most easily accessible, with the bone just
beneath the skin, and neither blood vessels nor
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,NASM
nerves are in the vicinity.
Mean cell volume (MCV) is calculated using the following formula:
A. (Hgb / RBC) × 10
B. (Hct / RBC) × 10
C. (Hct / Hgb) × 100
D. (Hgb / RBC) × 100 -Correct Answer ✔B. MCV is the average "volume" of the
red cells. This is
obtained by dividing the Hct or packed cell volume
(PCV) by the red blood cell (RBC) count in millions per
microliter of blood and multiplying by 10. The MCV is
expressed in cubic microns (μm3) or femtoliters (fL).
What term describes the change in shape of erythrocytes seen on a Wright's-stained
peripheral blood smear?
A. Poikilocytosis
B. Anisocytosis
C. Hypochromia
D. Polychromasia -Correct Answer ✔A. Variation in shape of the erythrocytes on a
peripheral
blood smear is poikilocytosis. Anisocytosis refers to a
change in size. Hypochromia is an increase in central
pallor in erythrocytes. Polychromasia describes the bluish tinge of the immature
erythrocytes (reticulocytes) circulating in the peripheral blood.
Calculate the mean cell hemoglobin concentration (MCHC) using the following
values:
Hgb: 15 g/dL (150 g/L)
Hct: 47 mL/dL (0.47)
RBC: 4.50 × 106/μL (4.50 × 1012/L)
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A. 9.5% (.095)
B. 10.4% (.104)
C. 31.9% (.319)
D. 33.3% (.333) -Correct Answer ✔C. MCHC is the average concentration of Hgb
in red
cells expressed as a percentage. It expresses the ratio of the weight of Hgb to the
volume of erythrocytes and is calculated by dividing Hgb by the Hct, and then
multiplying by 100. A decreased MCHC indicates that cells are hypochromic. In
this example, (15 ÷ 47) × 100 = 31.9%. The reference range for MCHC is 32%-
36%.
A manual white blood cell (WBC) count was performed. A total of 36 cells were
counted in all 9-mm^2 squares of a Neubauer-ruled hemacytometer. A 1:10
dilution was used. What is the WBC count?
A. 0.4 × 10^9/L
B. 2.5 × 10^9/L
C. 4.0 × 10^9/L
D. 8.0 × 10^9/L -Correct Answer ✔A. The formula used for calculating manual
cell counts
using a hemacytometer is:
Number of cells counted × dilution factor × depth factor (10) divided by the area.
In this example, 36 × 10 × 10 = 3600 ÷ 9 = 400/mm^3 or 0.4 × 10^9/L.
When an erythrocyte containing iron granules is stained with Prussian blue, the cell
is called a:
A. Spherocyte
B. Leptocyte
C. Schistocyte
D. Siderocyte -Correct Answer ✔D. Siderocytes are red cells containing iron
granules
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and are visible when stained with Prussian blue.
A 7.0-mL ethylenediaminetetraacetic acid (EDTA) tube is received in the
laboratory containing only 2.0 mL of blood. If the laboratory is using manual
techniques, which of the following tests will most likely be erroneous?
A. RBC count
B. Hemoglobin (Hgb)
C. Hct
D. WBC count -Correct Answer ✔C. Excessive anticoagulant causes shrinkage of
cells;
thus, the Hct will be affected. RBC and WBC counts
remain the same, as does the Hgb content.
A 1:200 dilution of a patient's sample was made and 336 red cells were counted in
an area of 0.2 mm^2. What is the RBC count?
A. 1.68 × 1012/L
B. 3.36 × 1012/L
C. 4.47 × 1012/L
D. 6.66 × 1012/L -Correct Answer ✔B. RBC count = number of cells counted ×
dilution
factor × depth factor (10), divided by the area.
In this example, 336 × 200 × 10 = 672,000 ÷ 0.2 = 3.36 ×
106/mm^3 = 3.36 × 10^12/L.
What phagocytic cells produce lysozymes that are bacteriocidal?
A. Eosinophils
B. Lymphocytes
C. Platelets
D. Neutrophils -Correct Answer ✔D. Neutrophils are highly phagocytic and
release
lysozymes, peroxidase, and pyrogenic proteins.
NASM
ASCP MLS Hematology Exam 2025 Graded A+
Insufficient centrifugation will result in:
A. A false increase in hematocrit (Hct) value
B. A false decrease in Hct value
C. No effect on Hct value
D. All of these options, depending on the patient -Correct Answer ✔A. Insufficient
centrifugation does not pack down the
red blood cells; therefore, the Hct, which is the
volume of packed cells, will increase.
Variation in red cell size observed on the peripheral smear is described as:
A. Anisocytosis
B. Hypochromia
C. Poikilocytosis
D. Pleocytosis -Correct Answer ✔A. A mature erythrocyte is approximately 7-8
μm in
diameter. Variation in normal size is denoted by the
term anisocytosis. Hypochromia is a term that indicates increased central pallor in
erythrocytes, and poikilocytosis denotes variation in red cell shape.
Which of the following is the preferable site for bone marrow aspiration and
biopsy in an adult?
A. Iliac crest
B. Sternum
C. Tibia
D. Spinous processes of a vertebra -Correct Answer ✔A. The iliac crest is the most
frequently used site for
bone marrow aspiration and biopsy. This site is the
safest and most easily accessible, with the bone just
beneath the skin, and neither blood vessels nor
NASM
,NASM
nerves are in the vicinity.
Mean cell volume (MCV) is calculated using the following formula:
A. (Hgb / RBC) × 10
B. (Hct / RBC) × 10
C. (Hct / Hgb) × 100
D. (Hgb / RBC) × 100 -Correct Answer ✔B. MCV is the average "volume" of the
red cells. This is
obtained by dividing the Hct or packed cell volume
(PCV) by the red blood cell (RBC) count in millions per
microliter of blood and multiplying by 10. The MCV is
expressed in cubic microns (μm3) or femtoliters (fL).
What term describes the change in shape of erythrocytes seen on a Wright's-stained
peripheral blood smear?
A. Poikilocytosis
B. Anisocytosis
C. Hypochromia
D. Polychromasia -Correct Answer ✔A. Variation in shape of the erythrocytes on a
peripheral
blood smear is poikilocytosis. Anisocytosis refers to a
change in size. Hypochromia is an increase in central
pallor in erythrocytes. Polychromasia describes the bluish tinge of the immature
erythrocytes (reticulocytes) circulating in the peripheral blood.
Calculate the mean cell hemoglobin concentration (MCHC) using the following
values:
Hgb: 15 g/dL (150 g/L)
Hct: 47 mL/dL (0.47)
RBC: 4.50 × 106/μL (4.50 × 1012/L)
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,NASM
A. 9.5% (.095)
B. 10.4% (.104)
C. 31.9% (.319)
D. 33.3% (.333) -Correct Answer ✔C. MCHC is the average concentration of Hgb
in red
cells expressed as a percentage. It expresses the ratio of the weight of Hgb to the
volume of erythrocytes and is calculated by dividing Hgb by the Hct, and then
multiplying by 100. A decreased MCHC indicates that cells are hypochromic. In
this example, (15 ÷ 47) × 100 = 31.9%. The reference range for MCHC is 32%-
36%.
A manual white blood cell (WBC) count was performed. A total of 36 cells were
counted in all 9-mm^2 squares of a Neubauer-ruled hemacytometer. A 1:10
dilution was used. What is the WBC count?
A. 0.4 × 10^9/L
B. 2.5 × 10^9/L
C. 4.0 × 10^9/L
D. 8.0 × 10^9/L -Correct Answer ✔A. The formula used for calculating manual
cell counts
using a hemacytometer is:
Number of cells counted × dilution factor × depth factor (10) divided by the area.
In this example, 36 × 10 × 10 = 3600 ÷ 9 = 400/mm^3 or 0.4 × 10^9/L.
When an erythrocyte containing iron granules is stained with Prussian blue, the cell
is called a:
A. Spherocyte
B. Leptocyte
C. Schistocyte
D. Siderocyte -Correct Answer ✔D. Siderocytes are red cells containing iron
granules
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, NASM
and are visible when stained with Prussian blue.
A 7.0-mL ethylenediaminetetraacetic acid (EDTA) tube is received in the
laboratory containing only 2.0 mL of blood. If the laboratory is using manual
techniques, which of the following tests will most likely be erroneous?
A. RBC count
B. Hemoglobin (Hgb)
C. Hct
D. WBC count -Correct Answer ✔C. Excessive anticoagulant causes shrinkage of
cells;
thus, the Hct will be affected. RBC and WBC counts
remain the same, as does the Hgb content.
A 1:200 dilution of a patient's sample was made and 336 red cells were counted in
an area of 0.2 mm^2. What is the RBC count?
A. 1.68 × 1012/L
B. 3.36 × 1012/L
C. 4.47 × 1012/L
D. 6.66 × 1012/L -Correct Answer ✔B. RBC count = number of cells counted ×
dilution
factor × depth factor (10), divided by the area.
In this example, 336 × 200 × 10 = 672,000 ÷ 0.2 = 3.36 ×
106/mm^3 = 3.36 × 10^12/L.
What phagocytic cells produce lysozymes that are bacteriocidal?
A. Eosinophils
B. Lymphocytes
C. Platelets
D. Neutrophils -Correct Answer ✔D. Neutrophils are highly phagocytic and
release
lysozymes, peroxidase, and pyrogenic proteins.
NASM
