DNA computing uses biological materials like DNA, biochemistry and molecular biology, in place of traditional silicon-based computer technology. Biomolecular computing or DNA computing is a fast developing area, research is going on to better understand the theory, experiments, applications of DNA computing. First important experiment regarding DNA computing was conducted in 1994 by Leonard Adleman. DNA computing is a new and alternative method for traditional silicon/conductor based technology used in computation.

What is DNA?

DNA stands for deoxyribonucleic acid and it acts as genetic code in almost all living organisms present on this planet earth. DNA or genetic codes are used by the cell or organism to form proteins by transcription and translation process. These proteins are building blocks of our life. Structure of DNA is double stranded helix; strands are anti parallel to each other and are made up of millions of bases or nucleotides. Each strand contains the many different combinations of four bases or nucleotides such as Adenine (A), Thymine (T), Cytosine (C) and Guanine (G).

Nucleotide Adenine always pairs with Thymine by two hydrogen bonds and Cytosine always base pairs with Guanine with the help of three hydrogen bonds. That is each strands complement each other. Interesting facts about DNA is that If we stretch out the DNA molecule present in body cells we can reach the moon 6000 times.

Origin of DNA Computing:

DNA computation utilizes the unique property of DNA for parallel computation. With correct set up and enough DNA content, can solve huge problems very easily using parallel search. Leonard Adleman first got the idea of using DNA in computational research techniques. Any number of DNA molecules can be formed by changing the base sequence, this property of the DNA has been utilized in DNA computing.

Need for DNA Computing:

1. Conventional or traditional silicon based computers have a limited speed and beyond a point cannot be miniaturize.
2. Information storage capacity of DNA molecule is much higher than the silicon chips. One cubic nanometre of DNA is sufficient to store 1bit information
3. Operations on DNA computing are parallel, test tube of DNA may contain around trillions of strands. Each operation is carried out in all the strands present in the test tube parallel.
4. 1 gram of DNA can store a huge amount of data such as 1 - 1014 MB of data; to listen to the same amount of data stored in a CD will require 163,000 centuries.
5. With the bases spaced at a distance of 0.35 nm in a DNA molecule, data density is around million Gbits/inch in a DNA computer. Whereas data density is around 7Gbits/inch in a typical high performance HDD.

Advantages of a DNA Computer:

1. DNA computers are light weight computers.
2. Power or electricity required by the DNA computers are very less, power is needed only to prevent the DNA from denaturation.
3. DNA computers can solve the hardest problems very quickly when compared to the traditional silicon computers.

Disadvantages of DNA Computer:

1. DNA computer takes much time to solve simple problems when compared to traditional silicon computers.
2. DNA computers take longer time to sort out the answers to a problem than it took to solve the same problem.
3. Sometimes there may be an error in the pairing of nucleotides present in the DNA strands.


DNA computing field is in its infancy stage, still the applications of this technology is not fully understood. This field as any other field also has got many obstacles and drawbacks.

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