Abstract: Systems, including compositions and methods, for measuring pH, particularly in cells, organelles, and other samples. The compositions include pH-sensitive fluorescent and fluorogenic 2?,7?-dialkylfluorescein derivatives and associated nonfluorescent precursor compounds. The compositions may permit ratiometric measurement in the excitation spectrum and the emission spectrum. The methods include adding a precursor compound to a sample cell, incubating the sample cell to release the free indicator, illuminating the sample cell, and detecting the fluorescence response of the free indicator.

Abstract: Systems, including compositions and methods, for measuring pH, particularly in cells, organelles, and other samples. The compositions include pH-sensitive fluorescent and fluorogenic 2′,7′-dialkylfluorescein derivatives and associated nonfluorescent precursor compounds. The compositions may permit ratiometric measurement in the excitation spectrum and the emission spectrum. The methods include adding a precursor compound to a sample cell, incubating the sample cell to release the free indicator, illuminating the sample cell, and detecting the fluorescence response of the free indicator.

Abstract: Systems, including compositions and methods, for measuring pH, particularly in cells, organelles, and other samples. The compositions include pH-sensitive fluorescent and fluorogenic 2′,7′-dialkylfluorescein derivatives and associated nonfluorescent precursor compounds. The compositions may permit ratiometric measurement in the excitation spectrum and the emission spectrum. The methods include adding a precursor compound to a sample cell, incubating the sample cell to release the free indicator, illuminating the sample cell, and detecting the fluorescence response of the free indicator.

Abstract: Systems, including compositions and methods, for purifying and/or labeling proteins or other molecules of interest and/or for assaying the conformational and/or binding states of such molecules.