Abstract: Methods and compositions are provided for detecting nucleic acid sequences. Probes comprising a crosslinking agent are combined with a sample which may comprise a target sequence which is complementary to the probe. Hybridization is allowed to occur between complementary sequences. The crosslinking agent is activated. Covalent bonds are formed between the probe and the target sequence if they are hybridized to one another. The crosslinked nucleic acids can then be detected to indicate the presence of the target sequence. Also provided are kits comprising reagents.