What is DNA Computing, DNA Computers & Its Techniques?

DNA computing and DNA computers are breakthrough technologies that are still under research and development. We have curated this post that will help you in learning about these techniques in a broader perspective. However, there are many who will say that it is a biology subject, but it is not. Read more about this technology>


What is DNA Computing?

DNA computing is a computing technique where DNA molecule can be used for computing instead of silicon that is used nowadays for making chips and microprocessor. This concept was first discovered by Leonard Adleman in 1994 when he was able to solve Hamilton path problems with the help of DNA.


We all know that the Human body is made up of cells and each cell contains 23 pairs of Chromosomes or 23*2 = 46 total number of chromosomes. In addition, each chromosome constitutes 2 DNA strands, i.e. the double helix model of DNA. So, in total there are 46*2 = 92 strands of DNA.

1 cell = 46 chromosomes = 92 strands of DNA

DNA is present in all living organisms, even a single drop of water is made up of trillions of DNA strands. This means DNA is plenty in nature and is in much greater amount than Silicon. The idea of computation through molecules was first laid down by Richard Feynman in 1959. However, practically, a successful example was given by Adleman which shown that DNA molecules can be used for computation.

DNA computing


DNA Computing Techniques

There are several DNA computing techniques that were developed in course of time. However, all the techniques require labwork with DNA strands that limits its greater usability. Let us first go through the biological structure of DNA and discuss further with DNA computation techniques.


DNA Structure

In the human body, DNA stores information that is passed from one generation to next. It also provides instructions to cells for their proper multiplication and growth. In genetic coding, according to Watson Crick’s law, the DNA is represented by A (Adenine), T (Thymine), G (Guanine), and C (Cytosine). The A and G as shown in the picture form a pair of purines and C and T form pyrimidines where A is a complement to T, and C is a complement to G.

DNA computing

How Adleman solved the Hamilton path problems?

As you have seen in the above image, there are four letters – A, T, G and C by which DNA genetic coding can be easily represented. Adleman used these four letters to solve the Hamilton Path problem or generally known as Traveling salesman problem. He used DNA strands to represent seven cities in his model. In addition, he used sequences of the four letters – A, T, G, and C to further represent possible flight path and cities.

Then, he mixed all these biological molecules together in a test tube. He, then waited a few seconds to get all the possible combinations of DNA strands. These DNA strands represented all the possible answers to his problem. So, in his test tube, he has all the answers, now the only job that’s left is to search for the right answers by eliminating wrong answers. He did this by performing chemical reactions with all these answers. All these steps lead to the right answers following the right flight paths to connect all the seven cities.


Computing Techniques

DNA computing is a computation technique that is very smart, fast and it helps to do parallel computation with DNA. There are several procedures that are followed nowadays to carry out computation based on DNA. Some of them use different DNA bases like – DNAzymes, enzymes, and Toehold exchange. These different bases can be used for making logic gates. After logic gates are manufactured then other tasks are easy like its analogous Silicon.

However, we can use any base for making logic gates, but, mostly the DNA computing can be seen clearly by dividing into three stages – Encoding, Molecular operations, and extraction. Let’s us discuss all these stages one by one so that you understand the complete strategy of performing DNA computation.


Encoding is a technique of converting the information into coding form. It is the first and important step of computation based on DNA.  This technique affects the answers that we may derive according to our problem. It can be further divided into two categories – Encoding with weights, Encoding without weights.

Molecular Operations

There are several operations that can be performed on DNA to get the correct answer. These are:-

  1. Electrophoresis – It is a technique to extract strands according to their length. In this technique, an electric field is passed in the prepared solution with DNA strands. The strands that are longer in size separates out collecting to one side of the solution.
  2. Denaturation – It is a method in which the solution of DNA is heated up so that strands of DNA separate with each other. We explained above that DNA has a double helix model and two strands stick together with hydrogen bonds. When we heat the tube containing DNA, the hydrogen bonds broke down due to heat energy and its strands separate from each other. This whole process is termed as Denaturation of DNA.
  3. Annealing – In this method, double strands are formed by making complementary strands to attach because of hydrogen bonding between them. Annealing is also known as hybridization where the denaturized DNA is cooled so that its complementary strands stick tightly to each other again.
  4. Polymerase chain reaction (PCR) – With this process, several copies of DNA are produced. One can make millions of strands from a single strand by using the PCR technique. Thus, we get an amplified output of DNA is obtained where several clones of DNA are produced.


Extraction is the last step in which the strands are separated out eliminating the wrong strands. Given a test tube of DNA, it is possible to extract only those that are required by following molecular operations on DNA. Usually, a complement of the strand is caused to anneal the solution. This causes the correct pattern to anneal while other patterns will remain dissolved in the solution.


What are DNA Computers?

DNA computing

DNA computer is a special type of computer that uses molecules i.e. DNA strands to solve problems like the computers used nowadays. But, DNA computer is very different in its functionality as it works biochemically unlike silicon-based computers. The computation process of DNA computers evolve reactions that are explained above in detail.

Silicon Vs DNA Computers

DNA computers have many advantages over Silicon-based computers that are used nowadays. Let’s discuss how DNA computers will be more advantageous than Silicon-based computers.

  • Speed – The Speed of DNA computers is faster than silicon-based computers. This is because DNA can compute very fast. It can solve complex problems in very less time.
  • Miniaturization – DNA computers are many times smaller in size than Silicon-based computers.
  • Parallel Computation – DNA computers can solve many problems at the same time. Moreover, large problems can be divided into many small problems and these can be solved easily by DNA computers. However, this is rarely possible with silicon-based computers.
  • Low-Price – The cost of solving a problem with DNA computer can be very less expensive as compared with silicon-based computers.
  • Environment-friendly – DNA computers don’t use toxic materials and also don’t consume electricity. Electricity is usually made with non-renewable resources that causes a lot of pollution. Thus, it can solve many problems in one go.
  • Large Data Capacity – This world’s whole data can be kept in a single DNA based computer. However, It is not at all possible with silicon-based computers.


We hope that this post helped a lot in learning about DNA computing and its technique, DNA computers and how they are helpful for future generations. Please like, share and comment below to help us write more posts for you regarding new inventions and technologies.