Hybridization reaction:
As double-stranded DNA is heated a temperature is reached at that the two reaction strands divided. This procedure is known as denaturation. The temperature at that half of the DNA molecules have denatured is known as the melting temperature or Tm for that DNA if the temperature is now lowered and falls below the Tm, the two corresponding strands will form hydrogen bonds with each other once more to reform a double-stranded molecule. This procedure is known as renaturation (or reannealing). In reality, double-stranded structures can form among any two single-stranded nucleic acid molecules (DNA-RNA, DNA-DNA, RNA-RNA) provided in which they have sufficient complementary nucleotide sequence to make the double-stranded molecule stable under the conditions used. The general name given to these procedures is hybridization and the double-stranded nucleic acid product is known as a hybrid.