Phagocytosis by phagocytes (such as macrophages, dendritic cells and neutrophils) is essential for a variety of biological events, including tissue remodeling and continuous clearance of dying cells, but also immunity.

Phagocytosis can be measured in vitro by measuring the engulfment of a substrate by phagocytic cells. Various substrates can be used, including red blood cells, E. coli and Zymosan particles (yeast).

Erythrocytes (red blood cells) are commonly used in phagocytosis tests. For FcR mediated phagocytosis, erythrocytes are first opsonized with serum or IgG before being added to the phagocytes. After removal of the non-phagocytic erythrocytes, the red blood cells engulfed by the phagocytic cells are counted manually (expressed as phagocytic index or phagocyte-engulfed erythrocytes). This method of manual counting is very cumbersome, time consuming and difficult when testing a large number of samples.

Our phagocytosis assay kits do not require manual counting of erythrocytes. Instead, the cells are lysed and detected by a plate reader.