The liquid portion of an anticoagulated blood sample is known as what?

The liquid portion of an anticoagulated blood sample is known as plasma. Plasma is a yellowish fluid that makes up about 55% of total blood volume and contains water, electrolytes, proteins, hormones, and waste products. When blood is drawn into a tube containing an anticoagulant—substances that prevent clotting—plasma separates from the blood cells and remains in liquid form. This is crucial for various laboratory tests that require plasma to analyze the components without the interference of clotting.

In contrast, serum is the liquid that remains after blood has clotted and the blood cells and clotting factors have been removed, making serum different from plasma. Whole blood refers to the complete form of blood, containing both the liquid (plasma) and the cellular components such as red blood cells, white blood cells, and platelets. Blood cells can be understood as the cellular components in blood, which again do not represent the liquid portion. Hence, plasma is the correct term for the liquid part of an anticoagulated blood sample.