This invention is directed to methods, kits and compositions pertaining to PNA Molecular Beacons. PNA Molecular Beacons comprise self-complementary arm segments and flexible linkages that promote intramolecular or intermolecular interactions. In the absence of a target sequence, PNA Molecular Beacons facilitate efficient energy transfer between the linked donor and acceptor moieties of the probe. Upon hybridization of the probe to a target sequence, there is a measurable change in at least one property of at least one donor or acceptor moiety of the probe which can be used to detect, identify or quantitate the target sequence in a sample.