The yeast phagocytosis assay serves as a foundational tool for directly visualizing and quantifying a phagocyte’s ability to bind and internalize foreign targets. Here, we present a protocol for analyzing phagocytosis in mouse peritoneal macrophages. We describe steps for yeast staining, phagocytosis of stained yeast, hematoxylin staining of macrophages, and light microscopy imaging. We then detail procedures for phagocytic metric analysis, which are also applicable to any phagocytic cells. This protocol can also be used for time-lapse visualization of phagocytosis. • Instructions for mouse peritoneal macrophage isolation for yeast phagocytosis assay • Steps for staining yeast, performing phagocytosis, and light microscopy imaging • Metric calculations to determine the quality and quantity of cell phagocytosis ability Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. The yeast phagocytosis assay serves as a foundational tool for directly visualizing and quantifying a phagocyte’s ability to bind and internalize foreign targets. Here, we present a protocol for analyzing phagocytosis in mouse peritoneal macrophages. We describe steps for yeast staining, phagocytosis of stained yeast, hematoxylin staining of macrophages, and light microscopy imaging. We then detail procedures for phagocytic metric analysis, which are also applicable to any phagocytic cells. This protocol can also be used for time-lapse visualization of phagocytosis.
Changaei et al. (2026) studied this question.