Hemocytometry

Question 1

The numerical evaluation of formed elements in blood is called:

A. Coagulation
B. Electrophoresis
C. Hematocrit
D. Hemocytometry

Answer 1

D. Hemocytometry

Question 2

In Thoma pipettes, the color of the bead for the RBC pipette is:

A. White
B. Red
C. Blue
D. Green

Answer 2

B. Red

Question 3

The dilution factor for RBC pipette when filled to 0.5 mark is:

A. 1:10
B. 1:20
C. 1:100
D. 1:200

Answer 3

D. 1:200

Question 3

Which WBC diluting fluid contains glacial acetic acid and gentian violet?

A. 1% HCl
B. 1–3% Acetic Acid with Gentian Violet
C. Tuerk’s fluid
D. NSS

Answer 3

B. 1–3% Acetic Acid with Gentian Violet

Question 3

Which of the following RBC diluting fluids is considered the best and preserves morphology?

A. Gower’s
B. Hayem’s
C. Dacie’s (Formol Citrate)
D. NSS

Answer 3

C. Dacie’s (Formol Citrate)

Question 4

The normal WBC count in conventional units is:

A. 4.0–6.0 x 10⁶/µL
B. 4.5–11.0 x 10³/µL
C. 4.0–6.0 x 10¹²/L
D. 4.5–11.0 x 10⁶/µL

Answer 4

B. 4.5–11.0 x 10³/µL

Question 5

The depth of the Improved Neubauer counting chamber is:

A. 0.05 mm
B. 0.1 mm
C. 0.2 mm
D. 0.5 mm

Answer 5

B. 0.1 mm

Question 6

The volume of the central large square of the Improved Neubauer is:

A. 0.004 μL
B. 0.02 μL
C. 0.1 μL
D. 0.9 μL

Answer 6

C. 0.1 μL

Question 7

Which counting chamber is used for low cell counts such as eosinophils, CSF, and leukopenic counts?

A. Improved Neubauer
B. Speirs-Levy
C. Fuchs-Rosenthal
D. Thoma

Answer 7

C. Fuchs-Rosenthal

Question 8

In cell counting, which rule applies?

A. Count cells on bottom and right lines
B. Count cells on top and left lines
C. Count cells on all borders
D. Ignore all border-touching cells

Answer 8

B. Count cells on top and left lines

Question 9

What is the diluting fluid that prevents rouleaux formation and precipitation of protein.

Answer 9

Gower’s Solution

Question 9

What is the counting chamber with 9 large squares and a ruled area of 9mm²

Answer 9

Improved Neubauer

Question 10

What is the correction formula used when nucleated RBCs are present in a WBC count?

Answer 10

Corrected WBC = (Uncorrected WBC × 100)
—————————————————————- (100 + NRBC per 100 WBC)

Question 11

What is the RBC index that expresses the average volume (size) of RBC?

Answer 11

Mean Corpuscular Volume (MCV)

Question 12

What RBC index is expressed in g/dL and used in classifying anemias together with MCV?

Answer 12

Mean Corpuscular Hemoglobin Concentration (MCHC)

Question 13

RBC Count Formula:

Answer 13

         Area x Depth x Dilution Factor

or

RBC= Cells Counted x 10 x 200 x 5

or

RBC= Cells Counted x 10000

5 is the area correction factor
10 is the depth correction factor
200 is the dilution factor

Question 13

WBC Count Formula:

Answer 13

Area x Depth x Dilution Factor

or

WBC= Cells Counted x 50

4 = area
0.1 = depth
1/20 = dilution factor

Question 13

Compute MCV:
MCV = (Hct × 10) ÷ RBC count

👉 Given Hct = 45%, RBC = 5 × 10¹²/L

Identify if its normocytic, hypochromic, or hyperchromic

Answer 13

MCV = (45 × 10) ÷ 5 = 90 fL (Normocytic)

Question 14

Compute MCH:
MCH = (Hgb × 10) ÷ RBC count

👉 Given Hgb = 15 g/dL, RBC = 5 × 10¹²/L

Identify if its normocytic, hypochromic, or hyperchromic

Answer 14

MCH = (15 × 10) ÷ 5 = 30 pg

Question 14

Compute MCHC:
MCHC = (Hgb × 100) ÷ Hct

👉 Given Hgb = 15 g/dL, Hct = 45%

Identify if its normocytic, hypochromic, or hyperchromic

Answer 14

MCHC = (15 × 100) ÷ 45 = 33 g/dL (Normochromic)

Question 15

The dilution factor of the WBC pipette is:

A. 1:20
B. 1:100
C. 1:20
D. 1:200

Answer 15

C. 1:20

Question 16

What is the composition of Hayem’s fluid?

A. Sodium chloride, sodium sulfate, mercuric chloride
B. Sodium chloride, sodium sulfate, mercuric chloride
C. Ammonium oxalate, distilled water
D. Glacial acetic acid, gentian violet

Answer 16

B. Sodium chloride, sodium sulfate, mercuric chloride

Question 17

What is the composition of Dacie’s fluid?

A. Sodium chloride, sodium sulfate, mercuric chloride
B. Sodium citrate, formalin
C. 40% formalin, 3% trisodium citrate
D. Ammonium oxalate and distilled water

Answer 17

C. 40% formalin, 3% trisodium citrate

Question 18

Which WBC diluting fluid lyses RBCs and stains nuclei of WBCs?

A. 1% HCl
B. NSS
C. 1–3% Glacial acetic acid with gentian violet
D. Hayem’s

Answer 18

C. 1–3% Glacial acetic acid with gentian violet

Question 18

The calculation factor used in RBC counts is: A. 200 B. 10,000 C. 100 D. 50

Answer 18

B. 10,000

Question 19

What is the composition of Tuerk’s solution? A. Ammonium oxalate and distilled water B. Glacial acetic acid, gentian violet C. Sodium chloride, sodium sulfate, mercuric chloride D. NSS only

Answer 19

B. Glacial acetic acid, gentian violet

Question 19

How many WBC squares are counted for a WBC count? A. 5 B. 9 C. 4 D. 25

Answer 19

C. 4

Question 19

The area counted for RBCs in Improved Neubauer is: A. 4 large corner squares B. Central large square divided into 25 medium squares C. 5 medium squares (4 corners + center) of central large square D. All 25 squares

Answer 19

C. 5 medium squares (4 corners + center) of central large square

Question 20

The calculation factor used in WBC counts is: A. 200 B. 2,000 C. 50 D. 10,000

Answer 20

C. 50

Question 21

n the WBC pipette, the bead color is: A. Red B. White C. Blue D. Green

Answer 21

B. White

Question 22

It has 2 identically ruled platforms with a raised ridge on both sides of the 2 platforms on which a cover glass is placed.

Answer 22

Improved Neubauer

Question 22

Which fluid is commonly used as a diluent for platelet counting? A. Dacie’s fluid B. Hayem’s C. NSS D. 1% Ammonium oxalate

Answer 22

D. 1% Ammonium oxalate

Question 22

Which solution is used for eosinophil counting in a hemocytometer? A. Hayem’s B. Phloxine diluting fluid C. NSS D. Acetic acid with gentian violet

Answer 22

B. Phloxine diluting fluid

Question 23

The space between the top of the platform & the cover glass is ________.

Answer 23

0.1 mm

Question 23

What is the total ruled area of the hemocytometer platform?

Answer 23

9 mm²

Question 23

What are the dimensions of each large square in the hemocytometer?

Answer 23

1 mm wide x 1 mm long

Question 24

How many large squares are there in each platform of the hemocytometer?

Answer 24

9 large squares

Question 25

What is the volume of the entire ruled area of the hemocytometer?

Answer 25

0.9 µL

Question 26

What is the volume of 1 large square in the hemocytometer?

Answer 26

0.1 µL

Question 27

The 4 corner large squares of the hemocytometer are subdivided into how many intermediate (tertiary) squares?

Answer 27

16 intermediate squares or tertiary squares These squares are for WBC counts

Question 28

Which squares are used for WBC counts in the hemocytometer? The 4 corner large squares (subdivided into 16 tertiary squares each)

Answer 28

The 4 corner large squares (subdivided into 16 tertiary squares each)

Question 29

How many tertiary/intermediate squares is the middle large square divided into?

Answer 29

25 tertiary or intermediate squares

Question 30

Each tertiary/intermediate square in the middle large square is further subdivided into how many smaller squares?

Answer 30

16 smaller squares

Question 31

What is the volume of the middle large square?

Answer 31

0.1 µL

Question 32

What is the volume of each of the 25 tertiary squares in the middle large square?

Answer 32

0.004 µL

Question 33

What is the total volume of 5 tertiary squares in the middle large square?

Answer 33

0.02 µL

Question 34

True or False Cells that touch the top & left lines should be counted.

Answer 34

True

Question 35

True or False Cells that touch the bottom & right lines should be ignored.

Answer 35

True

Question 36

What are the 3 WBC Diluting Fluid?

Answer 36

- 1-3% Acetic Acid with Gentian Violet - 1% HCl - Tuerk's

Question 36

What are the 7 RBC Diluting Fluids?

Answer 36

- Dacie's (Formol Citrate) - Hayem's - Gower's - Toisson's Fluid - Normal Saline Solution (NSS) - Bethel's - 3.8 % Sodium Citrate

Question 37

This RBC Diluting Fluid keeps for a long time; acts as the preservative; preserves the morphology; BEST diluting fluid

Answer 37

Dacie's (Formol Citrate)

Question 38

This RBC Diluting Fluid usually develops yeast colonies & produces clumping of cells but can stand for long periods of time and non-corrosive.

Answer 38

Hayem's

Question 38

This RBC diluting fluid has high specific gravity; stains WBC but supports the growth of fungi.

Answer 38

Toisson's Fluid

Question 38

What are the 3 types of Counting Chamber?

Answer 38

- Fuchs-Rosenthal - Speirs-Levy - Improved Neubauer

Question 39

This RBC diluting fluid prevents rouleaux formation & precipitation of protein

Answer 39

Gower's

Question 39

This RBC diluting fluid is stable; acts as a preservative; used in emergency cases; prevents rouleaux formation

Answer 39

Normal Saline Solution