New fluorescent labels: 4- and 7-chlorofluorescein.
A new mixture of 4- and 7-chlorofluorescein were synthesized by condensation of resorcinol with 3-chlorophthalic anhydride in the presence of methanesulfonic acid or zinc chloride. These regioisomers were successfully separated by chromatography. The photophysical properties were examined and their absorption and emission maxima at long wavelength, high fluorescence quantum yield, and narrow emission bandwidth were found, highly favorable for detecting multiple target substances in the same sample. Furthermore, 4(7)-chlorofluorescein was found to be strongly pH-dependent between 4.0 and 8.0, and could be used as pH-sensitive fluorescent probe to measure intracellular pH.
Ge
Feng-Yan
FY
School of Pharmaceuticals and Biotechnology, Tianjin University, Tianjin, 300072, PR China.
Yan
Xi-Long
XL
Yan
Fan-Yong
FY
Pan
Hui-Ying
HY
Chen
Li-Gong
LG
D005452:Fluoresceins / Q000138:chemical synthesis / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration
C510158:4-chlorofluorescein; C510159:7-chlorofluorescein; D005452:Fluoresceins; D005456:Fluorescent Dyes