2 ',7 '-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein as a dual-emissionfluorescent indicator of intracellular pH suitable for argon laserconfocal microscopy

摘要

The widely used fluorescent probe 2',7'-bis-(2-carboxyethyl)-5(6)-carboxy (BCECF) serves as a pH-sensitive indicator in classical microscopy. Characteristics of BCECF were studied and a way of employing the probe in a confocal laser scanning microscope equipped with an argon laser at 488 nm was developed, based on the fact that the emission fluorescence spectra are pH-dependent with spectral maximum shift from 518 to 529 nm. Optical filters for the dual-emission ratio method were set to 506 and 529 nm. pH values measured inside a single cell of Saccharomyces cerevisiae were similar to those obtained with other pH estimation methods.