The term for enhancement of phagocytosis by coating of foreign particles with serum proteins is

• A. opsonization.
• B. agglutination
• C. solubilization
• D. chemotaxis

Answer: (A)

Enhancement of phagocytosis by coating foreign particles with serum proteins is called opsonization. When pathogens are opsonized, antibodies (especially IgG) or complement fragments like C3b bind to their surface. Phagocytes have receptors for the Fc region of IgG and for C3b, so this coating provides a tangible handle that accelerates recognition and uptake. The presence of these opsonins lowers the barrier to engulfment, making phagocytosis more efficient and rapid. Other terms describe different processes—agglutination is the clumping of particles, solubilization relates to dissolving immune complexes, and chemotaxis is cell movement toward chemical signals—so they don’t directly explain the coating that enhances phagocytosis.