Final answer:
The clear yellow portion of a blood specimen with anticoagulant is plasma, which contains water, dissolved substances, antibodies, and coagulation factors, including fibrinogen.
Step-by-step explanation:
The clear yellow portion of a blood specimen with anticoagulant is called plasma. When blood is centrifuged, the blood cells and platelets move to the bottom of the tube, forming a layer known as the buffy coat. The top layer, which is the plasma, includes 90 percent water, substances responsible for maintaining the body's pH and osmotic load, and blood coagulation factors and antibodies. A distinctive feature of plasma is the presence of fibrinogen, a key clotting factor absent in serum. Serum, essentially plasma devoid of coagulation factors, lacks fibrinogen. Understanding these distinctions is pivotal in clinical diagnostics, as plasma and serum serve as valuable mediums for assessing various biochemical markers and ensuring accurate medical evaluations. Unlike serum, plasma contains fibrinogen, a clotting factor. Serum is essentially plasma without these coagulation factors.