Melting curve analysis is an assessment of the dissociation characteristics of double-stranded DNA during heating. As the temperature is raised, the double strand begins to dissociate leading to a rise in the absorbance intensity, hyperchromicity. The temperature at which 50% of DNA is denatured is known as the melting temperature. Measurement of melting temperature can help us predict species by just studying the melting temperature. This is because every organism has a specific melting curve.
The information gathered can be used to infer the presence and identity of single-nucleotide polymorphisms (SNP). This is because G-C base pairing have 3 hydrogen bonds between them while A-T base pairs have only 2. DNA with mutations from either A or T to either C or G will create a higher melting temperature.
The information also gives vital clues to a molecules mode of interaction with DNA. Molecules such as intercalators slot in between base pairs and interact through pi stacking. This has a stabilizing effect on DNAs structure which leads to a raise in its melting temperature. Likewise, increasing salt concentrations helps diffuse negative repulsions between the phosphates in the DNAs backbone. This also leads to a rise in the DNAs melting temperature. Conversely, pH can have a negative effect on DNA's stability which may lead to a lowering of its melting temperature.