Nucleic acid thermodynamics is the study of how
temperature affects the
nucleic acid structure of double-stranded
DNA (dsDNA). The melting temperature (
Tm) is defined as the temperature at which half of the DNA strands are in the
random coil or single-stranded (ssDNA) state.
Tm depends on the length of the DNA molecule and its specific
nucleotide sequence. DNA, when in a state where its two strands are dissociated (i.e., the dsDNA molecule exists as two independent strands), is referred to as having been
denatured by the high temperature.