[Electron-autoradiographic demonstration of intra- and extracellular bactericidal activity of polymorphonuclear...

A technique for the determination of intra- and extra-cellular bactericidal activity of neutrophils has been suggested. A mixture of neutrophils and bacteria was incubated for 30 min and subsequently 3H-uridine was added to the incubated mixture. If phagocytized and extracellularly located bacteria remain alive they incorporate 3H-uridine. Killed bacteria fail to incorporate 3H-uridine. Intra- and extracellular killing capacity of neutrophils is determined by the content of labelled and unlabelled bacteria in radioautographs.