Exp 06
Counting of RBCs [400x]¶
-
We use Hayem's Solution which is an isotonic fluid that that maintains tonicity, acts as a preservative and discourages clumping of blood.
-
Draw blood gently up to 0.5 mark on the pipette.
- Draw and fill in Hayem's fluid up to 101 mark and homogenize the blood with the fluid thoroughly by rotating the pipette in the horizontal position. The red bead aids in mixing.
- Discard the fiirst few drops of the fluid as it contains only dilution fluid.
- Charge the chamber with the sample by gently touching the tip of the pipette on the surface of the counting platform in contact with the edge of the cover slip. A small amount of fluid will be drawing in automatically by surface tension and capillary action. There should not be any air bubbles.
- Once the haemocytometer is charged, view it under 400x magnification.
-
Similar process as WBC Counting, we will only focus on the 4 corner squares. Each corner square has 16 boxes, we count the number of cells within each box using the L - Rule.
-
Total number of WBC's per MicroLiter is given by (D*N)/V
- Dilution Factor is 200, Volume is 0.02 MicroLiter.
- Total Number of WBCs = N * 10000 Cells
Common Reasons for False High Results:¶
- Dilution Fluid taken below mark (Insufficient Dilution)
- Overloading
Common Reasons for False Low Results:¶
- Excessive Dilution
- Insufficient Loading