DNA is composed of units called nucleotides arranged into two long polynucleotide chains, resulting in a double helical structure. Nucleotides contain a phosphate group, a sugar group and a nitrogen base. There are four types of nitrogen bases namely adenine (A), thymine (T), guanine (G) and cytosine (C). The arrangement of these bases establishes the genetic codon. The difference in the nucleotide sequences is the reason why organisms differ from one another. In eukaryotic cell, the DNA is localized to the nucleus.
DNA is an essential component of the mechanism for heredity. The nucleotide sequences carry information regarding different biological processes. The genetic codons encode proteins essential for biological function. This genetic information is transmitted to the next generation during cell division. The amplification of very long fragments of genomic DNA requires template DNA of very high quality. In some cases, amplification failure may be due to poor template quality. This particular quality of genomic DNA is prepared to ensure reliable amplification of long DNA fragments.
