Restriction enzymes, of which now more than 1000 are known, are sequence-specific. Restriction enzymes are also used in DNA fingerprinting . A crucial property of the double helix is the ability to separate the two strands without disrupting covalent bonds. This makes it possible for the strands to separate and reform under physiological conditions. The specificity of the process is determined by complementary base pairing.
Hybridization refers to the formation of double stranded nucleic acids.
It is often used to describe the formation of a DNA-RNA hybrid, as illustrated here. But annealing of DNA is also hybridization. Northern Blotting, which involves DNA-RNA hybridization. Because DNA is such a long molecule, its tertiary structure is very complex. However, we can discuss some known structures.