title: The fluorescent probe BCECF has a heterogeneous distribution in sea urchin eggs.
abstract: Sea urchin eggs were loaded with the pH-sensitive fluorescent probe BCECF. Homogenization of these eggs, followed by centrifugation, resulted in 25% of the total homogenate fluorescence remaining with the pellet. Fluorescence microscopy revealed brightly fluorescing punctate organelles whose fluorescence was not quenched by acidification. The excitation spectrum of intracellular BCECF was markedly red-shifted compared to probe calibrated in buffer. Model excitation spectra based on a two compartment model mimicked the intracellular BCECF spectrum, therefore, supporting the possibility that organelles in sea urchin eggs accumulate large amounts of BCECF in a relatively pH-insensitive form.
authors.affiliation: Department of Zoology, Arizona State University, Tempe 85287.
authors.forename: N M
authors.initials: NM
authors.lastname: Mozingo
authors.forename: D E
authors.initials: DE
authors.lastname: Chandler
mesh_terms: D000818:Animals; D002138:Calibration; D002451:Cell Compartmentation; D003593:Cytoplasm / Q000378:metabolism; D004072:Digitonin / Q000494:pharmacology; D005306:Fertilization / Q000502:physiology; D005452:Fluoresceins / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D005471:Fluoroscopy; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D009550:Nigericin / Q000494:pharmacology; D009865:Oocytes / Q000378:metabolism* / Q000648:ultrastructure; D015388:Organelles / Q000378:metabolism; D012617:Sea Urchins / Q000196:embryology / Q000378:metabolism* / Q000502:physiology
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; D004072:Digitonin; D009550:Nigericin