Practical 1 Hematocrit Value PDF

Hematocrit value is the percentage ratio of blood cell volume (RBCs volume) to the total blood volume (packed cell volume). PCV = (RBCs volume/ total blood volume) ×100. Separation of blood cells from plasma by centrifugation, depending on difference in specific gravity (RBCs. “with SG 1090” will si...

Hematocrit value is the percentage ratio of blood cell volume (RBCs volume) to the total blood volume (packed cell volume). PCV = (RBCs volume/ total blood volume) ×100. Separation of blood cells from plasma by centrifugation, depending on difference in specific gravity (RBCs. “with SG 1090” will sink into the bottom with WBCs & platelets “SG 1060” above it & plasma “SG 1030” on top) Materials: -70% alcohol, lancet & syringe -Centrifuge apparatus -Capillary tube or Wintrobe tube containing anticoagulant Method (steps): Two methods are available: 1 Sterilize the thumb with 70% alcohol & prick its tip with sterile lancet. 2 Fill ≥ 2/3 of the capillary tube with blood by putting it perpendicular on oozing blood (allowing blood to enter the tube by capillarity & gravity). 3 Close outer end of the tube by wax (air bubbles disappear during centrifugation). -Centrifuge the tube at rate of 3000 cycle/minute for 3-5 minutes. -Get the tube out & determine the PCV from scale on the apparatus by putting the tube parallel to the graduation with lower level of RBCs. on (0) line & upper level of plasma on (100%) line; PCV is the reading at upper level of RBCs. 1-Sterilize the skin over a vein & take a venous blood sample by syringe. 2 Evacuate blood in a Wintrobe tube containing anticoagulant (e.g. Na oxalate or Na citrate). 3 Centrifuge the tube at rate of 3000 cycle/minute for 15 minutes. -get the tube out & determine the PCV from the graduation on the tube; PCV = (RBCs volume / total blood sample volume) x 100.