Nucleic acid hybridization can be used to identify particular DNA sequences using a nucleic acid probe. The technique takes advantage of DNA's property of complementary base pairing - if DNA is separated into single strands, the complementary strands will reform into double helices when conditions are right. A nucleic acid probe is a short, radioactively labelled single-stranded DNA or RNA molecule that binds to complementary nucleic acid sequences, allowing them to be identified. Genetic mapping uses genetic markers and recombination frequency during meiosis to locate genes on chromosomes and establish the relative distances between genes.