Red Blood Cell Count
Principle: Blood is diluted 1 in 251 in a solution of formal citrate reagent which lyses the white blood cells and platelets, red blood cells are counted microscopically using an improved neubauer ruled counting chamber and the number of red blood cells per liter of blood calculated.
Test Procedure for Red blood cell count
- I measured 5.0ml of formal citrate diluting fluid and dispensed it into a tube
- I added 0.02ml of well – mixed anticoaqulated venous blood and mix
- Assembled the counting chamber
- Re – mixed the diluted blood sample using a capillary Pasteur pipette, filled one of grids of the chamber with the sample.
- I left the chamber undisturbed for 20 minutes. To prevent the drying of the fluid, I placed the chamber in a Petri-dish and covered with a lid.
- Dry the underside of the chamber and placed it on the microscope stage. Using the 10 x objective focused the rulings of the grid and brought the central square of the chamber into view. Changed to the 40 x objective and focused the small red blood cells.
- I counted the red blood cells in the small squares of the central big square
- The number of red blood cells in a litre of blood was reported.