Provided is a family of intramolecularly quenched imaging agents for use inboth in vivo and in vitro imaging thatcontain at least one enzymatically cleavable oligopeptide and two fluorophoresor a fluorophore and a quencher. When subjectedto proteolytic cleavage, at least one fluorophore is unquenched and becomescapable of producing a fluorescent signal uponexcitation with light of an appropriate wavelength. Also provided are in vivoand in vitro imaging methods using such imaging agents.
