The dideoxynucleoside triphosphates (ddNTPs) terminate the bio-polymerization of DNA and become essential chemical component of DNA sequencing technology which is now basic tool for molecular biology research. In this method the radiolabeled or fluorescent dye labeled ddNTP analogues are being used for DNA sequencing by detection of the terminated DNA fragment after single labeled ddNTP incorporation into DNA under PCR conditions. This report describes the syntheses of rationally designed novel amino-functionalized ddNTP analogue such as Pyrrolidine nucleoside triphosphates (prNTPs), and their polymerase activities with DNA polymerase by LC–MS and Gel-electrophoretic techniques. The Mass and PAGE analyses strongly support the incorporation of prNTPs into DNA oligonucleotide with Therminator DNA polymerase as like control substrate ddNTP. As resultant the DNA oligonucleotide are functionalized as amine group by prNTP incorporation with polymerase. Hence prNTPs provide opportunities to prepare demandable conjugated DNA with other biomolecules/dyes/fluorescence molecule without modifying nucleobase structure.