A Simple, Reproducible, Inexpensive, Yet Old-Fashioned Method for Determining Phagocytic and Bactericidal Activities of Macrophages

Macrophages (Mϕ) play a pivotal role in the protection system by recognizing and eliminating invading pathogenic bacteria. Phagocytosis and the killing of invading bacteria are major effector functions of Mϕ. Although the phagocytic and bactericidal activities of Mϕ have been analyzed via several methods using a light microscope, a fluorescence microscope, or a fluorescence-activated cell sorter, expensive materials and equipment are usually required, and the methods are rather complicated. Moreover, it is impossible to determine both the phagocytic and bactericidal activities of Mϕ simultaneously using these methods. In this review, we describe a simple, reproducible, inexpensive, yet old-fashioned method (antibiotic protection assay) for determining the phagocytic and bactericidal activities of Mϕ.