After the primer is in place on a single, unwound polynucleotide strand, DNA polymerase wraps itself around that strand, and it attaches new nucleotides to the exposed nitrogenous bases.

It requires a known primer, normal deoxynucleosidetriphosphates (dNTPs) and modified di-deoxynucleotidetriphopates (ddNTPs) and a DNA polymerase for obtaining >500 bp long sequence ... Genome ...