title: Direct measurement of phagolysosomal esterase activity.
abstract: A new method of directly measuring esterase activity within phagolysosomes has been developed. Decanoyl fluorescein- binding microspheres were prepared and phagocytosed by human peripheral neutrophils. Within phagolysosomes lysosomal esterase hydrolyzed decanoyl fluorescein on the microspheres, causing the conversion of decanoyl fluorescein- binding microspheres (non-fluorescent) into fluorescein- binding microspheres (fluorescent). The activity of phagolysosomal esterase in intact neutrophils was assayed by the measurement of the fluorescence intensity without rupturing cells. By use of a flow cytometer, esterase activity within phagolysosomes in single cells was measured.
mesh_terms: D004950:Esterases / Q000032:analysis*; D005434:Flow Cytometry; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D006868:Hydrolysis; D008027:Light; D008247:Lysosomes / Q000201:enzymology*; D008863:Microspheres; D009504:Neutrophils / Q000201:enzymology; D010586:Phagocytes / Q000201:enzymology*; D012542:Scattering, Radiation; D013997:Time Factors
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; C044754:decanoyl fluorescein; D004950:Esterases