1. A membrane-bound vesicle formed in a cell when a phagocyte engulfs a particle, bacterium, or other foreign material.
Usage: biology; cell biology; technical

Examples

• When a white blood cell encounters a bacterium, it forms a phagosome to contain and digest the invader.
• The phagosome fuses with lysosomes to create a phagolysosome, which breaks down the engulfed material.
• Scientists studied how pathogens escape from the phagosome to avoid being destroyed by the immune system.
• The formation of a phagosome is a critical step in the process of phagocytosis.
• Under the microscope, researchers could observe the phagosome surrounding the foreign particle.