This document discusses the determination of red blood cell indices including packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). It describes the macrohematocrit or Wintrobe tube method for determining PCV which involves centrifuging a blood sample and measuring the ratio of packed red cells to total blood volume. Formulas are provided for calculating MCV from PCV and RBC count, MCH from hemoglobin and RBC count, and MCHC from hemoglobin and PCV. Normal ranges are listed for each index.

1. AIM: Determination of RED CELL
INDICES

2. 1. Packed cell volume(PCV)
2. Mean corpuscular volume(MCV)
3. Mean corpuscular hemoglobin(MCH)
4. Mean corpuscular hemoglobin concentration(MCHC)
5. Color index (CI)

3. Determination of Hematocrit(PCV)

4. • Hematocrit literally means ‘blood separation’.
• It measures the percentage of volume of packed
red cells.
• So it is also known as Packed cell volume(PCV).

5. Methods:
1. Macrohematocrit method (Wintrobe Method)
2. Microhematocrit method

6. Macrohematocrit method (Wintrobe Method)

7. Apparatus Required:
1. Wintrobe tube
2. Centrifuge machine
3. Pasteur pipette
4. Pricking apparatus to get venous blood
sample
5. EDTA vial

8. Wintrobe tube:
• 110 mm long, narrow, thick walled tube with 3mm
internal bore.
• Graduated from 0-10 cm with graduation both in
ascending and descending order on 2 sides of tube.
• The scale with the markings from 0-10 from above
downwards is used in ESR determination and from below
upward is used for Hematocrit (PCV) determination.

10. Procedure :
1. Under aseptic condition get a venous blood sample.
2. Carefully mix the blood sample in EDTA vial by
repeated inversion.
3. Fill the Wintrobe tube with the help of Pasteur
pipette to the 10 cm mark ( which represent 100%).
4. Place the Wintrobe tube in the centrifuge machine,
and other wintrobe tube filled with water on the
opposite side so as to balance it.
5. Turn the centrifuge on to the slow speed and then
gradually increase the speed.

11. 6. Centrifuge for 30 minutes at 3000 rpm.
7. After 30 minutes stop the centrifuge machine.
8. Take out the Wintrobe tube and note the readings
directly off the graduation.

13. Mean Corpuscular Volume(MCV)
• Average or mean volume of a single red blood
cell expressed in cubic micrometers.

14. How MCV is calculated ?
• Formula:
MCV = PCV X 10
RBC count
Normal range: 74 – 95 um3

15. Mean Corpuscular Hemoglobin(MCH)
• Average hemoglobin content (weight of Hb) in
a single red blood cell in picograms(pg).

16. How MCH is calculated ?
• It is calculated from the following basic values:
I. RBC count in million/mm3
II. Hb in gm%
• Formula:
MCH = Hb in gm% X 10
RBC count
Normal range: 27 – 32 pg

17. Mean Corpuscular Hemoglobin
Concentration(MCHC)
• MCHC represents the relationship between
the red cell volume and its degree or
percentage saturation with hemoglobin.

18. How MCHC is calculated ?
• Formula:
MCHC = Hb in gm% X 100
PCV
Normal range: 30 – 36 %