What is plasma called when the clotting proteins have been removed?

Plasma is referred to as serum when the clotting proteins, such as fibrinogen, have been removed. This process typically occurs after blood has clotted, allowing the liquid portion to separate from the cellular components and the clotting factors. Serum consists primarily of water, electrolytes, hormones, and various proteins, but notably excludes the clotting factors that are present in plasma. This distinction is important in medical tests and diagnostics, as the presence or absence of these proteins can significantly affect laboratory results and interpretations.

The other options do not accurately describe this liquid component of blood after clotting proteins have been removed. Blood refers to the entire fluid in the circulatory system, which includes cells, serum, and clotting factors. Platelets are a type of cell that play a crucial role in clotting but are not a liquid component. Hemoglobin is a protein within red blood cells responsible for oxygen transport, not a part of the liquid matrix of blood or plasma.