The invention provides nucleic acid hybridization probes having improved detectability that include a plurality of first segments consecutively complementary to a target nucleic acid sequence and, between neighboring first segments, a nucleic acid spacer segment which is not complementary to the target nucleic acid sequence and which may include labeled nucleic acid residues. Also provided by the invention are methods for making the probes, methods for using the probes, and compositions of matter that include the probes hybridized to target nucleic acid molecules.