Melting temperature of DNA is:-

Denaturation or melting of two DNA strands means the separation of the two strands of DNA. In this process, hydrogen bonds between the complementary base pairs are broken, leading to separation Melting temperature (Tm) of DNA- that temperature at which half of the DNA duplex gets dissociated to become single-stranded. Tm of DNA is between 85-95degC. *Primers with melting temperatures in the range of 52-58degC generally produce the best results. *Tm is propoional to G C pairs because there are three hydrogen bonds between G & C, as compared to the two hydrogen bonds between A & T. So more G C content gives thermostability to DNA. *For every 10 % increase in G C content, melting temperature raises by 5degC.