Blood Separation in a Centrifuge: How Does it Work?

Question:

When anticoagulated blood is spun down in the centrifuge, how does it separate?

a) Plasma rises to the top, followed by buffy coat, and then red blood cells at the bottom

b) Red blood cells rise to the top, followed by plasma, and then buffy coat

c) Plasma remains in the middle, surrounded by buffy coat, with red blood cells at the top and bottom

d) It does not separate in the centrifuge

Answer:

When anticoagulated blood is spun in a centrifuge, the lightest component, the plasma, rises to the top. This is followed by the 'buffy coat' layer of leukocytes and platelets, and then the heaviest component, the red blood cells, at the bottom.

When anticoagulated blood is spun in a centrifuge, it separates into different layers according to their densities. The plasma, consisting largely of water, various substances required for the body's functions, and coagulation factors, rises to the top since it's the lightest component. This is followed by a 'buffy coat,' which is a thin, pale layer of leukocytes (white blood cells) and platelets. The heaviest elements, the erythrocytes or red blood cells, settle at the bottom. Therefore, the correct response to the question would be a) Plasma rises to the top, followed by buffy coat, and then red blood cells at the bottom.