What is the main difference between serum and plasma?

The primary distinction between serum and plasma lies in the presence of fibrinogen. Plasma is the liquid component of blood that remains after coagulation factors have been removed, meaning it contains fibrinogen and other clotting proteins, which are essential for blood clotting. This is significant for various medical procedures and tests where the understanding of these components is vital.

In contrast, serum is the fluid that separates out after blood has clotted and the clot has been removed. As a result, serum lacks fibrinogen and other clotting factors because they are consumed in the clotting process. This difference plays an important role in laboratory settings where specific components of blood are analyzed for diagnostic purposes. Understanding this distinction helps in choosing the appropriate specimen based on the test requirements, as certain tests may require plasma while others may specifically require serum.

The other answer choices contain inaccuracies or misunderstandings about serum and plasma, such as the notions about electrolytes and the clarifying properties of both fluids. It’s essential to have a clear understanding of these components and their significance in phlebotomy and laboratory diagnostics.