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).
.jpg)
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.
