pH-sensitive cyanine dyes for biological applications

A series of functionalized, water-soluble, pH-sensitive pentamethine cyanine (Cy(TM)5) dyes has been designed and synthesized. These probes are fluorescent in acidic media but are non-fluorescent in an alkaline environment. Subtle changes to the structure of these probes can lead to pronounced changes in the pKa of these probes. These probes have been utilized in a cellular environment to detect localized changes in PH using the IN Cell Analyzer, a confocal imager formatted for imaging of cell-based assays.