Laboratory Activity 7: HEMATOCRIT DETERMINATION and CALCULATION OF RED BLOOD CELL INDICES

Question 1

refers to the ratio of the blood volume of erythrocytes to that of the whole blood.

Answer 1

Hematocrit

Question 2

Although hematology analyzers are available, (?) is still done by many laboratories.

Answer 2

manual hematocrit determination

Question 3

The most commonly used manual method is the (?).

Answer 3

Microhematocrit method

Question 4

This method is considered as one of the simplest, most accurate and reproducible laboratory test.

Answer 4

Microhematocrit method

Question 5

Another manual procedure of measuring hematocrit is the historical (?)

Answer 5

Wintrobe method

Question 6

(Macrohematocrit method as it uses larger volume of blood).

Answer 6

Wintrobe method

Question 7

The red blood cell indices are calculations of the (?) of the red cells from the hemoglobin, hematocrit and red cell count values.

Answer 7

size and hemoglobin content

Question 8

The three common erythrocyte indices are the (?).

Answer 8

mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC)

Question 9

These indices have been widely used in the classification of (?).

Answer 9

anemia

Question 10

a) Macro method

Answer 10

anticoagulated venous blood

Question 11

b) Micro method

Answer 11

fresh capillary blood

Question 12

A. Macro Method by Wintrobe:
1. Fill the Wintrobe tube with (?) from the bottom using a Pasteur pipette.
2. Centrifuge tube at exactly (?).
3. Read (?) from the scale on the right side of the tube. (The figures begin from100 on top and end 0 at the bottom.)
4. Take care to read the level at the junction of the red cell layer. Do not include the (?) in the reading.
5. (?)

Answer 12

anticoagulated blood

3,000 rpm for 30 minutes

packed cell volume

buffy coat layer

Calculate

Question 13

Hematocrit (%) =

Question 14

B. Micro Method by Clay Adams:
1. Fill (?) with blood by capillary action approximately (?). If using a tube with a colored ring at one end, fill from the opposite end.
2. (?) at exterior of the tube.
3. Seal unfilled end (end with colored ring) with (?), forming a straight edge across the interior of the tube.
4. Centrifuge (open end near the center of the centrifuge) for (?).
5. Read results from a (?).
6. Express results in (?).

Answer 14

heparinized tube; 2/3 full (about 5 cm)

Wipe off blood

seal-ease clay, then with paraffin

5 minutes at 12,000 rpm

microhematocrit reader

% and in L/L

Question 15

C. Computation of Red Blood Cell Indices:
1. Compute for the (?) of your CBC results (from previous experiments) using these formulas: New CBC values may be given by your teacher for the purpose of these computations.
2. (?) the computed RBC indices and interpret based on the following

Answer 15

MCV, MCH and MCHC

Record

Question 16

Reference Ranges:
MCV:
MCH:
MCHC:

Answer 16

80 100 fL

27 32 pg

32 36 g/dL or 320 360 g/L