1.1 Basic Hematology Concepts and Laboratory Procedures

Question 1

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 these options, depending on the patient

Answer 1

• A. A false increase in hematocrit (Hct) value

Insufficient centri does not pack RBC, hence, Hct will increase

Hct (volume of packed cells)

Question 2

Variation in RBC size observed on the PBS is described as:
A. Anisocytosis
B. Hypochromia
C. Poikilocytosis
D. Pleocytosis

Answer 2

• A. Anisocytosis

inc RDW = inc anisocytosis

Question 3

Which of the following is the preferred site for bone marrow aspiration and biopsy in an adult?
A. Iliac crest
B. Sternum
C. Tibia
D. Spinous processes of a vertebra

Answer 3

• A. Iliac crest

it is the safest and preffered site for BM biopsy and aspiration

Question 4

MCV is calculation using the formula:
A. (Hgb / RBC) x 10 where Hgb in g/dL
B. (Hct / RBC) x 10
C. (Hct / Hgb) x 100
D. (Hgb / RBC) x 100

Answer 4

• B. (Hct / RBC) x 10

MCV is the average volume of RBCs

Question 5

What term describes the change in shape of erythrocytes seen on Wright-stained PBS?
A. Poikilocytosis
B. Anisocytosis
C. Hypochromia
D. Polychromasia

Answer 5

• A. Poikilocytosis

Question 6

Calculate the MCHC by using the following values:
* Hgb = 15g/dL (150 g/L)
* RBC = 4.50 x10^6 /uL (4.50x10^12/L)
* Hct = 47 mL/dL (0.47)

A. 9.5% (0.095)
B. 10.4% (0.104)
C. 31.9% (0.319)
D. 33.3% (0.333)

Answer 6

MCHC = (hgb/hct) x 100
normal MCV: 32% to 36%

Question 7

A manual WBC count was performed. In total 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. 0.4x10^9/L
B. 2.5x10^9/L
C. 4.0x10^9/L
D. 8.0x10^9/L

Answer 7

• A. 0.4x10^9/L

36x10x10 / 9 = 400

WBC count = no. cells x dF x depth factor 10 / area

Question 8

When an erythrocyte containing iron granules is stained with Prussian blue, the cell is called a:
A. Spherocyte
B. Leptocyte
C. Schistocyte
D. Siderocyte

Answer 8

• D. Siderocyte

Siderocytes are RBC containing iron granules

visible when stained with prussian blue

Question 9

A 7.0-mL 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. Hgb
C. Hct
D. WBC count

Answer 9

• C. Hct

excessive anticoagulant causes shrinkage of cells, hct will be affected.

Question 10

A 1:200 dilution of patient’s sample was made, and 336 RBCs were counted in an area of 0.2 mm^2. What is the RBC count?
A. 1.68x10^12/L
B. 3.36x10^12/L
C. 4.47x10^12/L
D. 6.66x10^12/L

Answer 10

• B. 3.36x10^12/L

RBC ct = 336x200x10 / 0.2
= 3.36x10^6 /mm^3 or 3.36x10^12/L

Question 11

What phagocytic cells produce lysozymes that are bacteriocidal?
A. Eosinophils
B. Basophils
C. Platelets
D. Neutrophils

Answer 11

• D. Neutrophils

neutrophils are highly phagocytic

Question 12

If the patient has a reticulocyte count of 7% and Hct of 20%, what is the corrected reticulocyte?
A. 1.4%
B. 3.1%
C. 3,5%
D. 14%

Answer 12

• B. 3.1%

corrected retics ct = (retics ct) (hct/45)

Question 13

A decreased osmotic fragility test would be associated with which of the following conditions?
A. Sickle cell anemia
B. Hereditary spherocytosis
C. Hemolytic disease of the fetus and newborn
D. Acquired hemolytic anemia

Answer 13

• A. Sickle cell anemia

OFT is decreased in numerous sickle cells & target cells

OFT is increased in presence of spherocytes which are prominent feature of HS, HDFN, Acquired hemolytic anemia.

Question 14

What effect would using a buffer at pH 6.0 have on a Wright-stained smear?
A. RBCs would be stained too pink
B. WBC cytoplasm would be stained too blue
C. RBCs would be stained too blue
D. RBCs would lyse on the slide

Answer 14

• A. RBCs would be stained too pink

pH is too low (<6.4), so RBCs take up more acidic dye (eosin) = too pink

Question 15

Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright-stained blood smear?
A. Basophilic stippling
B. Heinz bodies
C. Howell-Jolly bodies
D. Siderotic granules

Answer 15

• B. Heinz bodies

irregular, refractile, purple inclusions not visible in wright stain

Question 16

A falsely elevated Hct is obtained. Which of the following calculated values will not be affected?
A. MCV
B. MCH
C. MCHC
D. RDW

Answer 16

• B. MCH

MCH = (hgb/rbc) x10

Question 17

A miller disk is an ocular device used to facilitate counting of:
A. PLT
B. Retics
C. Sickle cells
D. NRBCs

Answer 17

• D. NRBCs

Question 18

SITUATION: RBC indices obtained on an anemic patient are as follows: MCV 88um^3 (fL); MCH 30pg; MCHC 34% (0.340). The RBCs on the PBS would appear:
A. Microcytic, hypochromic
B. Microcytic, normochromic
C. Normocytic, normochromic
D. Normocytic, hypochromic

Answer 18

• C. Normocytic, normochromic

all within normal referenc range
MCV = 80-100 fL
MCHC = 32-36%

Question 19

All of the following factors may influence the ESR, except:
A. Blood drawn from sodium citrate tube
B. Anisocytosis, poikilocytosis
C. Plasma proteins
D. Caliber of the tube

Answer 19

• A. Blood drawn from sodium citrate tube

EDTA & Sodium Citrate can be used without any effect on ESR

anisocytosis & poikilocytosis impede rouleaux formation, plasma proteins enhance rouleaux

Question 20

What staining method is used most frequently to stain and manually count reticulocytes?
A. Immunofluorescence
B. Supravital staining
C. Romanowsky staining
D. Cytochemical staining

Answer 20

C. Supravital staining

reticulum w/in retics consists of RNA w/c cannot be stained w/ wright

Question 21

The Coulter principle for counting of cells is based on the fact that:
A. Isotonic solutions conduct electricity better than cells do
B. Conductivity varies proportionally to the number of cells
C. Cells conduct electricity better than saline does
D. Isotonic solutions cannot conduct electricity

Answer 21

• A. Isotonic solutions conduct electricity better than cells do

Electronic cell (Coulter) counter use principle of electrical impedance

Question 22

A correction is necessary for WBC counts when NRBCs are seen on the PBS because:
A. WBC ct would be falsely lower
B. RBC ct is too low
C. NRBCs are counted as leukocytes
D. NRBCs are confused with giant PLTs

Answer 22

• C. NRBCs are counted as leukocytes

to correct: (uncor WBC ct / (NRBCs + 100) x 100

Question 23

Using an electronic cell counter analyzer, an increased RDW should correlate with:
A. Spherocytosis
B. Anisocytosis
C. Leukocytosis
D. Presence of NRBCs

Answer 23

• B. Anisocytosis

RDW is directly proportional with the degree of Anisocytosis

RDW ref range: 11.5% to 14.5%

Question 24

Given the following values, which set of RBC indices suggests spherocytosis?
A. MCV 76fL MCH 19.9pg MCHC 28.5%
B. MCV 90fL MCH 30.5pg MCHC 32.5%
C. MCV 80fL MCH 36.5pg MCHC 39.0%
D. MCV 81fL MCH 29.0pg MCHC 34.8%

Answer 24

• C. MCV 80fL MCH 36.5pg MCHC 39.0%

In spherocytosis, index most affected is MCHC >36%

Question 25

Which of the following statistical terms reflects the best index of precision when comparing with two CBC parameters?
A. mean
B. median
C. coefficient of variation
D. standard deviation

Answer 25

C. coefficient of variation

CV = (s / mean) x 100

sd describes distribution of sample observations
while CV is used to compare precision of tests with diff means

Question 26

Which of the following is considered a normal Hgb?
A. Carboxyhemoglobin
B. Methemglobin
C. Sulfhemoglobin
D. Deoxyhemoglobin

Answer 26

• D. Deoxyhemoglobin

Deoxyhgb is the physiological hgb that results from unloading O2

Question 27

Which condition will shift the oxyhemoglobin dissociation curve to the right?
A. Acidosis
B. Alkalosis
C. Multiple blood transfusions
D. Increased quantities of Hgb S or C

Answer 27

• A. Acidosis

Question 28

What is the major type of leukocyte seen in the PBS from a patient with aplastic anemia?
A. Segmented neutrophil
B. Lymphocyte
C. Monocyte
D. Eosinophil

Answer 28

• B. Lymphocyte

aplastic anemia = BM spotty with patches of normal cellularity

w/c results with absolute granulocytopenia, however lymphocyte production is less affected

Question 29

What is the normal WBC differential lymphocyte percentage (range) in the adult population?
A. 5-10%
B. 10-20%
C. 20-44%
D. 50-70%

Answer 29

C. 20-44%

normal adult percentage of lymphocytes in a WBC diff ct: 20-44%

Question 30

In which age group would be 60% lymphocytes be a normal finding?
A. 6 mos-2 yrs
B. 4-6 yrs
C. 11-15 yrs
D. 40-60 yrs

Answer 30

• A. 6 mos-2 yrs

reversal in the normal differential percentage or inverted differential

Question 31

Which of the following results on an automated differential suggests that a PBS should be reviewed manually?
A. Segs = 70%
B. Band = 6%
C. Mono = 15%
D. Eos - 2%

Answer 31

• C. Mono = 15%

monocyte count in a normal diff count: 1-8%

Question 32

Which is the first stage of erythrocytic maturationin which the cytoplasm is pink because of the formation of Hgb?
A. Reticulocyte
B. Pronormoblast
C. Basophilic normoblast
D. Polychromatic normoblast

Answer 32

• D. Polychromatic normoblast

In normal erythrocytic maturation, Hgb formation in the late polychromatic normoblast stage gives the cytoplasm a prominent pink coloration

Question 33

Which of the following can shift the Hgb oxygen dissociation curve to the right?
A. Increases in 2,3 DPG
B. Acidosis
C. Hypoxia
D. All of these options

Answer 33

• D. All of these options

kapag nangaliwa doon lang papait at baba ang relasyon ng anak 2,3 DPG

Question 34

Which of the following Hgb configurations is characteristic of Hgb H?
A. y4
B. a2-y2
C. B4
D. a2-B2

Answer 34

• C. B4

Hgb H structure: B4

remember Hb H-B, ppt of B-globin chains: alpha thalassemia (only one gene out of four is fuctioning)

Question 35

Autoagglutination of RBCs at RT can cause which of the following abnormal test results?
A. Low RBC ct
B. High MCV
C. Low Hct
D. All of these options

Answer 35

• D. All of these options