Synthesis and biological applications of two novel fluorescent proteins-labeling probes.

Two novel chlorinated fluoresceins 2',4',5',7'-tetrachloro-6-(5-carboxypentyl)-4,7-dichloro fluorescein succinimidyl ester (1G) and 2',4',5',7'-tetrachloro-6-(3-carboxypropyl)-4,7-dichlorofluorescein succinimidyl ester (2G) were synthesized as fluorescent probes for labeling proteins. Structures of target compounds and intermediates were determined via IR, MS, (1)H NMR and element analysis. The investigation in immunofluorescence histochemistry showed them had strong fluorescence, high photostability and good biocompatibility.