Friday, 27 March 2015

LPU scientist develops novel technology for DNA amplification

                  Parallel DNA polymerase chain Reaction (PD-PCR):

Polymerase chain reaction (PCR) is one of the revolutionary techniques which almost every molecular biology lab use for their specific application. Kary Mullis received the Nobel Prize in 1993 for this technique. Due to its high impact and application in biotechnology research, Kary Mullis was awarded the Nobel Prize within 8 years of its publication. In the same year, Richard J Roberts and Phillip A Sharp received the Nobel Prize for discovery of “split genes”, after waiting for 16 years. This will give you some idea of immense impact PCR has had worldwide. PCR is based upon utilizing the capability of DNA polymerase to synthesize new strand of DNA complementary to the offered template strand. This revolutionary technology has allowed researchers to advance their understanding of various phenomenons taking place at molecular level within a cell. The technique has been exploited to understand various processes in life science research including human genome project. In addition, it has been an indispensable component of various forensic science applications, the diagnosis of hereditary diseases and the detection and diagnosis of infectious diseases.
The gene amplification market is predicted to grow to heights by 2017 suggesting a robust industrial prospective of PCR. Indian scientists Dr. Vikash Bhardwaj and Dr. Kulbhuhsan Sharma at India's Lovely Professional University and the Institute of Nuclear Medicine and Allied Sciences, Delhi respectively have recently published a novel PD-PCR (Parallel DNA PCR) technique which claims to amplify DNA in a parallel orientation, challenging the dogma that PCR can only be initiated when primers are aligned in an anti-parallel way. They have shown that the Taq DNA polymerase, enzyme used to amplify DNA during PCR, can even extend the oligonucleotide primer annealed to single stranded DNA in a parallel complementary manner. The details of how their proposed parallel DNA PCR differs from the conventional PCR can be found in journal F1000Research (http://f1000research.com/articles/3-320/v1).
In a personal communication, Bhardwaj and Sharma wrote to us “Our fundamental knowledge of DNA structure is based on the Watson-Crick model of DNA double helix, in which two polynucleotide chains running in opposite direction are held together by hydrogen bonds between the nitrogenous bases. Conformational polymorphism of DNA is now extending beyond the Watson-Crick double helix. After initial discovery of DNA by Friedrich Miescher in 1868, it took 85 more years to solve the accurate structure of DNA. One reason behind this delay was the assumption that DNA is an inert molecule and it might not have key biological function. Later, the independent work of few scientists (Griffith, Erwin Chargaff, Avery et al, Hershey and Chase) proved the biological function of DNA which created interest in scientific community to find out more molecular details about DNA. James Watson, Francis Crick, Maurice Wilkins received Noble Prize in 1963 for solving structure of  B-form of DNA. B-form is considered as the “hero of molecular biology” in which two complementary DNA strands runs in antiparallel directions and many of the molecular biology techniques are based on complementary binding of two strands of nucleic acid.
Conventional knowledge says that only antiparallel complementary primers can amplify DNA but through our research, we want to highlight that parallel complementary primers can also initiate a reaction. Till now, only a bunch of reports have talked about “Parallel stranded DNA”.  Ours is the first study showing that synthesis of DNA can happen also in a parallel direction. We report for the first time that from a single-stranded DNA template, two different but related PCR products can be synthesized. We are happy to share that within a very short span of time, our article is listed as one of the highly assessed article on F1000Research with more than 4000 views and 700 downloads worldwide.
We used to spend hours together discussing the possibilities of amplification of DNA template using parallel primers. We enthusiastically ran the reaction with different combination of  parallel primers and found amplification similar to control reaction. We were very excited! However, as it was something in contrast to what scientists all over the globe believe, we reconfirmed the phenomenon using various approaches. It was only after the concrete validation that we submitted our study to F1000 research. We strongly believe that researchers will understand the significance of our work, which will lead to a clearer understanding of the various biological phenomenons. This research is revolutionary one which will be helpful in tracing all errors hitherto committed. This new knowledge will definitely open a way in better understanding of remedies for fatal diseases with more probes.