Total Red Blood Cell (Erythrocyte)Counting

 

Total Erythrocytes count

This test measures the number of red blood cells, or erythrocytes, in your blood. Red blood cells play a critical role in moving oxygen from your lungs to the rest of your body and returning carbon dioxide to your lungs to be exhaled.

A red blood cell (RBC) count is typically done as part of a complete blood count. This test is done to check for a variety of medical conditions.

 

Material required

• Ø  Compound microscope
• Ø  Hemocytometer
• Ø  Red blood cell diluting pipette with rubber tube
• Ø  Counting chamber
• Ø  Glass cover
• Ø  Cotton
• Ø  Blood sample
• Ø  Red blood cell diluting fluid ( Hayem’s solution)

 

Hayem’s diluting solution is prepared as follows:

• Hgcl₂               0.25gm
• Na₂so₄        0.5gm 
• Nacl           2.5gm
• Distilled water 100ml

 

Procedure

• Ø  Take blood in the pipette up to 0.5 marks and wipe the excess blood with cotton.
• Ø  The tip of the pipette is immediately dip into the diluting fluid and draw fluid into tube up to 1o1 mark.
• Ø  Keep the pipette horizontally by finger thumb and shake pipette gently.
• Ø  Place Hemocytometer under microscope and cover with cover slip over the chamber. Find the counting chamber with 10X objective. Discard 2,3  drops of  solution and put  few drops of solution into counting  chamber and start count the cells under 40X objective lens. 4 corner and 1 center square to be count for total erythrocyte count.
• Ø  The counted number of cell is multiplied by 10000 and result is expressed in million/cubic mm.

 

Calculation:

Area of chamber = 1/5mm square

Depth of chamber =0.1 mm = 1/10mm

Diluting factor= 1:200

Total area = 1/10000 cubic mm.

Counting chamber

SPICEIS	NO. OF BLOOD (million/cmm)
Cattle	6-8
Sheet	8-12
Goat	12-20
Dog	6-8
Cat	6-8
Chicken	2.5-3.3
Human (male)	5-6
Human (female)	4-5