Abstract
This chapter describes three methods for measuring the bactericidal activity of neutrophils. All utilize colony counting techniques to quantify viable bacteria. A simple "one-step" protocol provides a composite measure of phagocytosis and killing, while a "two-step" protocol that separates extracellular and intracellular bacteria allows calculation of rate constants for both of these processes. We also present a method for selectively monitoring the long-term survival of bacteria within the phagosome. This may have application in identifying resistant strains and searching for compounds that sensitize pathogens to destruction.