In the packed cell volume (PCV) procedure, after centrifugation, which line on the scale indicates the PCV percent?

In the packed cell volume (PCV) procedure, after centrifugation, which line on the scale indicates the PCV percent?

• A. The interface between the red blood cells and plasma on the scale.
• B. The line at the 0 mark on the scale.
• C. The line at the 100 mark on the scale.
• D. The bottom edge of the capillary tube.

Answer: (B)

The main idea is that the PCV percent is read from where the red blood cell layer meets the plasma on the scale printed on the capillary tube. After centrifugation, the cells form a compact bottom layer and the plasma sits on top; the height of the red cell column relative to the total tube height determines the PCV. The line at that interface on the scale gives the percentage of blood volume occupied by red cells. The bottom edge of the capillary tube marks how far the red cell column extends, but the PCV value comes from the interface line, not from the tube’s bottom edge.

The main idea is that the PCV percent is read from where the red blood cell layer meets the plasma on the scale printed on the capillary tube. After centrifugation, the cells form a compact bottom layer and the plasma sits on top; the height of the red cell column relative to the total tube height determines the PCV. The line at that interface on the scale gives the percentage of blood volume occupied by red cells. The bottom edge of the capillary tube marks how far the red cell column extends, but the PCV value comes from the interface line, not from the tube’s bottom edge.