When centrifuging an anticoagulated tube the liquid at the top of the tube will be:.

The resulting liquid at the top is the plasma.

Explanation:

This question seeks to compare the difference between the methods of preparation of plasma and that of serum.

To obtain serum from a blood sample, the blood sample is collected in a plain bottle (usually red capped) and the blot is allowed to clot by leaving it standing/alone for about 15 - 20 minutes after collection. This clotted blood is then centrifugated at 2000 - 3000 revolution per minutes (rpm) for 10 minutes. The liquid at the top after centrifugation here is the serum.

In preparing plasma, the blood sample is collected in a bottle that has anticoagulant like the EDTA bottle (which contains an anticoagulant called EDTA) and then inverted slightly about 7 times to allow the EDTA mix with the blood. This blood sample is then centrifugated at 2000 - 3000 for 15 mins. The resulting liquid at the top is the plasma.