Methods for DNA sequencing:

Two major techniques have been devised to sequence DNA; the chemical technique that is also called the Maxam-Gilbert technique after its inventors and the chain termination techniques (also known as the Sanger dideoxy techniques after its inventor). The chain termination technique is now the method commonly used because of its simplicity and speed. In this procedure, the DNA to be sequenced is prepared as a single-stranded molecule so in which it can act as a template for DNA synthesis in the sequencing reaction. The E. coli DNA polymerase I is used to copy this DNA template. However, this enzyme requires a primer to begin synthesis. An primer used can be either a DNA restriction fragment complementary to the single-stranded sample or it can be a short sequence of complementary DNA which has been synthesized chemically a synthetic oligonucleotide.