How to calculate maximal melting temperature of DNA

DNA secondary structure, the double helix, is held together by hydrogen bonds between base pairs. Specifically, adenine bases pair with thymine bases and guanine bases pair with cytosine bases. Heating a DNA sample disrupts these hydrogen bonds, thus “unwinding” the double helix and denaturing the DNA. Because three hydrogen bonds form between guanine/cytosine base pairs and two hydrogen bonds form between adenine/thymine base pairs, more energy is required to denature the former. DNA with a greater number of guanine/cytosine base pairs denatures at a higher temperature than adenine/thymine base pairs. In fact, there is a linear relationship between the amount of guanine and cytosine in a given DNA molecule, known as the GC content, and the temperature at which the double helix will denature, called the melting point (denoted as tm). What affects the melting temperature of DNA? The melting temperature depends on a variety of factors, such as the length of DNA (shorter pieces tend to melt more easily), the nucleotide sequence composition, salt concentration (ionic strength of the added salt) and generally lies between 50°C and 100°C. How length of DNA effects melting temperature of DNA How GC content influence DNA melting temperature How to calculate maximal melting temperature of DNA How to calculate GC content of DNA if melting temperature of DNA is known