A0.1 ml
B5 ml
C1 ml
D10 ml
Answer:
A. 0.1 ml
Read Explanation:
Overview of Haematocrit Measurement
The Haematocrit (Hct), also known as Packed Cell Volume (PCV), measures the proportion of red blood cells (RBCs) in the total blood volume.
It is a crucial haematological test used to diagnose conditions like anaemia (low haematocrit) and polycythemia (high haematocrit).
Capillary Tube Specifications
The standard method for manual haematocrit measurement uses the Wintrobe tube or capillary microhaematocrit tubes.
The capillary tube typically used in the microhaematocrit method is a small glass tube.
Capacity: These tubes are designed to hold approximately 0.05 mL (or 50 microlitres) of blood.
Measurement Process: The blood is drawn into the tube by capillary action, one end is sealed, and it is centrifuged at high speed (typically 10,000–15,000 rpm) for 3–5 minutes to separate the plasma from the packed red blood cells.