Figure 37.1: Principle of Di-Deoxy Method.

Step 5: A chase of polymerization reaction is performed in the presence of high concentration of NTPs to extend all non-terminated sequences into high molecular weight DNA. These high molecular sequences will not enter into the sequencing gel.

The different steps in labeling/termination protocol differ from sanger protocol after step1 and it has following steps:

Step 2: A limited amount of NTPs are added along with the one of the radiolabeled nucleotide to label the DNA through the length.

Step 3: The polymerease reaction is divided into 4 reactions.

Step 4: The polymerase reaction continues with 4 nucleotide and one ddNTPs. Synthesis is terminated at the specific ddNTPs (either A, G. C. T) to give DNA fragment of different length.