INNOVATIONS FROM THE EDGE - KPIT

Introduction
Have you ever thought of using DNA, which is
present inside your body to perform calculations
Out of question, isn't it Can you imagine that
probably DNA can be used to perform a square
root operation or can be used to compute roots of
a polynomial We all know DNA defines the
characteristic of a person and contains the genetic
instructions to perform the development and
functioning of the person. So maybe we can relate
this operation similar to a system, which has
predefined instructions on how to operate. The
term computer brings to our mind an image of a
monitor with a keyboard, RAM, ROM and so on.
The present computers perform computations
digitally on silicon-based microprocessors. What if
there is a computer that does not have any
particular shape nor does it have any hardware
but still performs computations more efficiently
than the present day computers Yes, such kinds
of computers are in development. They are called
DNA machines and the phenomenon is called DNA
computing.
History
In early 1950s, the physicist Richard Feynman first
proposed the idea of using living cells and
molecular complexes to construct submicroscopic
computers. Adleman was the first to
demonstrate the ability of DNA to perform
computations and form a bio-molecular machine.
DNA shows the ability to perform parallel
computing and DNA machines could be used for
solving hard computational problems, which
could be solved in minimum amount of time. DNA
machines can be logically made because the DNA
has a double helical structure and can be
connected on the desired sequence. Adleman first
computed the Hamiltonian path problem with this
bio-molecular machine and followed it by
computing similar problems. He also put
tremendous efforts in finding ways in efficiently
implementing these algorithms on these biomolecular
machines. The practical feasibility of
these DNA computers looks tough as of now,
however we cannot deny the computational
ability shown by these DNA molecules and there is
definitely a huge potential of research in this area.
32 TechTalk@KPITCummins, Volume 5, Issue 1, 2012
In 2002, researchers in Weizmann Institute of
Science in Rehovot, Israel developed a molecular
computer composed of enzymes and DNA
molecules instead of silicon chips. In April
2008,Yaakov Benenson and team announced in the
journal NATURE that they developed a DNA
computer coupled with input and output module
which is capable of diagnosing cancerous activity
within a cell.
The proposed DNA model computer shows its
advantage over the conventional silicon based
computers due to the following reasons.
l Perform millions of operations simultaneously
(parallel programming ability),
l Generate a complete solution set for the given
problem statement, and
l Efficient handling of large memory.
However, these machines have disadvantage also
such as:
l It takes many hours or even days for these
machines to complete the computation, and
l Generating solution set for simple problems may
require large amount of memory
These days DNA computers are being developed to
solve real life problems e.g. data encryption
standards (DES). These algorithms have already
been solved using the conventional computers in a
shorter time; however, the DNA based machines
are much flexible and cost effective.
Storage and Memory
Baum has proposed a method to make a large
addressable memory using DNA. The structure of
this proposed model is quite simple. DNA,
Deoxyribonucleic Acid of which genes in human
body is made up of, is where information is stored.
DNA molecules are composed of nucleotides. The
nucleotides are purines –adenine (A) and guanine
(G) and thymine (T) and cytosine(C) are
pyrimidines. According to Watson - Crick Model of
D N A , e a c h o f t h e components h a d a
complementary component- T is the complement
of A and vice versa. Similarly, C is the complement
of G and vice versa. Under appropriate conditions,
a single strand of DNA can become double
stranded