The determination of nucleotide or base sequence of DNA molecule is known as Dna Sequencing. At present DNA sequencing is possible for only one to long DNA fragments. DNA sequencing has become feasible as a result following important developments (1) the availability of restriction endouncleases development of highly sensitive gel electrophoretic techniques which can separate fragments different by one nucleotide only (2) the gene cloning and PCR techniques large quantities of individual DNA fragments and (4) the development relatively easy and rapid DNA sequencing called Maxam and Gilbert procedure and (2) enzymatic procedure