Bacterial Binding, Phagocytosis, and Killing: Measurements Using Colony Forming Units

Herein we provide a colony forming unit (CFU)-based counting method for quantitating the bacterial binding, phagocytosis, and killing capacity of phagocytes. Although these functions can be measured by immunofluorescence and dye-based assays, quantitating CFUs is comparatively inexpensive and easy to perform. The protocol described below is easily modified for use with different phagocytes (e.g., macrophages, neutrophils, cell lines), types of bacteria or opsonic conditions.