[3] Basic methods for the study of phagocytosis

Publisher Summary This chapter provides an overview of the basic methods available for the study of phagocytosis. The encounter of neutrophils with a microbe is functionally divided into four phases—namely, (1) attraction (directed and passive chemotaxis), (2) binding of the microbe to the phagocyte membrane (attachment), (3) ingestion (phagocytosis), and (4) bactericidal activity (killing). The viability of the suspension should be established, before any functional studies are performed on the isolated and purified phagocytic cells. The most popular viability assessment is by means of dye exclusion studies. The techniques for the measurement of phagocytosis can be divided into two broad categories: (1) those that assess phagocytic ingestion per se and (2) those assays that measure bactericidal activity of neutrophils. In the former technique, the various techniques can be grouped into two general classes: (1) the microscopic category, in which the extent of particle uptake by individual cells is determined directly and (2) the macroscopic (or bulk) category, in which measurements of a certain parameter are made on samples containing large numbers of cells.