Deoxyribonucleic acid (DNA) is the common structure that forms the basic building blocks of life. Every nucleated cell in our body contains a copy of the 3 billion letters that comprise our unique DNA sequence. DNA sequencing is the process by which the precise order of the adenines (A), cytosines (C), guanines (G), and thymines (T), which are the nucleotide bases that comprise this DNA code, are determined. The first organism sequenced was the 5386 bases pairs (bp) of bacteriophage X174 by Frederick Sanger and colleagues in 1978. Since then, progress has been extremely rapid, with the generation of the sequences of viruses and numerous bacteria, culminating in the global effort to determine the sequence of the human genome.