JC-D7 (JCD7; JC D7) is a novel and selective fluorescent probe/dye used for specific labeling of synthetic polyphosphate (polyP) in vitro as well as endogenous polyP in living cells. It demonstrated high selectivity for the labeling of polyP that was not
sensitive to a number of ubiquitous organic polyphosphates, notably RNA.
Use of JC-D7 allowed the real time detection
of polyP release from lysosomes in live cells. Furthermore, use of JC-D7 enabled the detection of increased levels of polyP in cells with Parkinson's
disease related mutations. Inorganic polyphosphate (polyP) is a polymer composed of many orthophosphates linked together by phosphoanhydride bonds. In addition to its important role in the function of microorganisms,
polyP plays multiple important roles in the pathological and
physiological function of higher eukaryotes, including mammalians. However, due to the siginificantly lower abundance of polyP in mammalian
cells when comparing to microorganisms, its investigation poses an
experimental challenge.