Phagocytosis is a fundamental cell biological process exhibited by a wide variety of cell types from single cell organ-isms,which rely on this for feeding,to phagocytes in higher animals,which rely on specialised immune cells for com-bating infecting micro-organisms.In the immune system,both macrophages and neutrophils play roles as phagocytes.Neutrophils are often called“professional phagocytes”because of their remarkable capacity for phagocytosis,beingable to internalise microscopic particles(diam 0.5-3 μm)of virtually any surface material.The efficiency and speedof phagocytosis is,however,increased by coating the surface of the particles with opsonins such as antibodies or thecomplement component C3bi(acting on β2 integrin receptors),and C3bi-accelerated phagocytosis by neutrophils is thefirst line of defence by the innate immune system in vivo,operating in advance of the slower production of antibodies.Understanding the mechanism of phagocytosis is,therefore,clearly an important goal. Phagocytosis is a fundamental cell biological process extracts by a wide variety of cell types from single cell organ-isms, which rely on this for feeding, to phagocytes in higher animals, which rely on special-like cells for com-bating infecting micro-organisms. In the immune system, both macrophages and neutrophils play roles as phagocytes. Neutrophils are often called “professional phagocytes ” because of their remarkable capacity for phagocytosis, beingible to internalize microscopic particles (diam 0.5-3 μm) of virtually any surface material. The efficiency and speedof phagocytosis is, however, increased by coating the surface of the particles with opsonins such as antibodies or the complication component C3bi (acting on β2 integrin receptors), and C3bi-accelerated phagocytosis by neutrophils is the first line of defense by the innate immune system in vivo, operating in advance of the slower production of antibodies. UNinding the mechanism of phagocytosis is, therefore, clearly an importan t goal.