Compared with serum, the protein electrophoretic pattern of plasma commonly shows which feature?

• A. Fibrinogen peak between the β- and γ-globulins
• B. Broad increase in the γ-globulins
• C. Fibrinogen peak with the α2-globulins
• D. Decreased albumin peak

Answer: (A)

When you compare plasma to serum, the key difference is that plasma contains fibrinogen, while serum does not because fibrinogen is converted to fibrin during clotting. On protein electrophoresis, this extra fibrinogen in plasma appears as a distinct band that migrates with the beta globulins—often described as a fibrinogen peak between the beta and gamma regions. Serum, having lost fibrinogen, shows no such band. So the characteristic feature of plasma is this fibrinogen peak between the beta and gamma globulins.