title: A simple quantitative fluorimetric assay of in vitro phagocytosis in human neutrophils.
abstract: In general the in vitro assays of phagocytosis rely on microscope counting or radioisotopic detection of ingested particles or microbiological counting of non-ingested bacteria. A very simple, rapid, highly quantitative method using fluorescein-labelled bacteria was described by Vray et al. (Scand. J. Immunol. (1980) 11, 147) for non-human phagocytes. We report here a modification of this method to increase its sensitivity, to make it more suitable for pharmacological studies. We also provide detailed experimental parameters for its use with human phagocytes. A suspension of fluorescein-labelled bacteria is incubated with human phagocytes; after incubation at 37 degrees C, the reaction is terminated with ice-cold Tyrode buffer solution, and the non-ingested bacteria are removed by lysis with lysozyme and the resultant cell suspension treated with the detergent TX-100. The fluorescence of the suspension is then measured. The modified method is sufficiently sensitive to permit the detection of bi-directional effects on phagocytosis of a known modulator of human phagocyte function.
mesh_terms: D001310:Auranofin / Q000494:pharmacology; D001770:Blood Bactericidal Activity; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D006801:Humans; D007700:Kinetics; D007958:Leukocyte Count; D008837:Micrococcus / Q000502:physiology; D009504:Neutrophils / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology; D017830:Octoxynol; D010587:Phagocytosis / Q000187:drug effects; D011092:Polyethylene Glycols / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013861:Thiocyanates
chemical_list: D005452:Fluoresceins; D013861:Thiocyanates; D001310:Auranofin; D011092:Polyethylene Glycols; D017830:Octoxynol; D016650:Fluorescein-5-isothiocyanate