By: Prashanth T 1nh02ec033

By: PRASHANTH T 1NH02EC033

• As long as there are cellular organisms, there will always be a supply of DNA. • The large supply of DNA makes it a cheap resource. • Unlike the toxic materials used to make traditional microprocessors, DNA biochips can be made cleanly. • DNA computers are many times smaller than today's computers.

* Purifying silicon is very expensive, hence the chip making. However, for DNA sequencing corroborates to purity, which is very cheap. •MOORE’S LAW establishes a limit on the miniaturization of silicon chips, but there are no limits DNA density in DNA computing.

FUNDAMENTALS ABOUT DNA STRUCTURE

DNA is deoxyribo nucleic acid and is the building block of all living beings It is a polynucleotide and has a double helical structure. It is made of nucleotides adenine(A),guanine(G),Thiamine(T) and cytosine( C). Adenine bonds only with thiamine and guanine bonds only with cytosine. The two helix are complimentary of each other

{To find the shortest path covering all cities only once.}

DELHI

To find a route between Mumbai and Kolkata

KOLKATA

MUMBAI

BANGALORE

CHENNAI

• Generate all possible routes. • Select itineraries that start with the proper city and end with the final city. • Select itineraries with the correct number of cities. • Select itineraries that contain each city only once.

STEP1:Encode the city names in short DNA sequences.Encode the Itineraries by connecting the city sequences for which the routes exist

MUMBAI DELHI BANGALORE CHENNAI KOLKATA

GCTACG CTAGTA TCGTAC CTACGG ATGCCG

The DNA molecules are generated by a machine called DNA synthesizer

GENERATION OF DIFFERENT ITINERARIES

Polymerase chain reaction is used to produce many copies of the DNA PCR is iterative and uses an enzyme called polymerase Polymerase copies a section of single stranded DNA starting at the position of the primer,which is DNA complimentary to one end of the Interested section.

Step 2: Sort the DNA by length and select the DNA whose length Corresponds to 5 cities.

Gel electrophoresis force the DNA through a gel matrix by using an electric field. DNA forces its way through the gel which slows down the DNA at different rates

STEP 3:Successively filter the DNA molecules by city,one city at a Time.

Affinity purification is done by attaching the compliment of the sequence in question to a substrate like magnetic bead. The DNA which contains the sequence hybridizes with the complement sequence on the beads Graduated PCR can also be used if we already have the sequence of city encodings.

As the complexity of the problem increases the amount of DNA required also increases exponentially. Since the operations are not deterministic but stochastically driven,there will be some statistical errors which limits the number of iterations. It could not operate on a surface, limiting its applications It required human intervention

Prof Lloyd Smith,Robert corn and Liman Wang of University of Wisconsin -Madison,US Published a paper in the journal NATURE on Jan 13,2000 Millions of DNA was anchored on a surface of glass coated with gold

Invented in 2001 by researchers in Weizmann Institute of science in Rehovot,Israel The team was headed by Prof Ehud Shapiro A single drop of water could hold trillion of machines. It could perform a billion operations per second It relied on ATP(adenosine triphosphate) for fuel It used DNA and enzymes as hardware ,software ,input and output

Invented in 2002 by scientists at Weizmann Institute of science,Israel Team led by Prof Ehud Shapiro The DNA molecule provides both the initial data and energy to complete computation An enzyme known as FOKL cleaves a piece of input molecule and releases the energy stored in the bonds It performs 330 trillion operations per second which is more than 1,00,000 times the fastest PC

Dr Leonard Adleman of University of Southern California,USA designed a DNA computer in 2002 The computer solves a complex problem with more than one million possible solutions. One strand of DNA was used to represent a problem It in turn generated trillions of other strands The computer weeds out invalid solutions until it is left with the correct solution.

In 2003,Columbia University researcher Milan Strojanovic developed a DNA computer used by NASA for health maintenance of astronauts. Richard J.Lipton,Daniel Boneh and Christopher T.Dunworth designed a DNA computer that cracked the US defence messages. Albert Libchaber of NEC research institute,Princeton,NJ used DNA to solve maximal clique problem. Wisconsin Researchers solved “satisfiability”problem Harold Craighead of Cornell Nanobiotechnology center has developed silicon alternatives for DNA electrophoresis. Nadrian C.Seeman of New York University used DNA to mimick the XOR gate behaviour.

The inputs are replaced by DNA.If the DNA at the input are a complementary strands they combine to give a 1. On April 28,2004 Ehud Shapiro constructed a DNA computer which when coupled with a input and output module is capable of diagnosing cancerous activity within a cell and release an anti-cancer drug.

Feature

DNA COMPUTER Unlimited

SILICON COMPUTER Limited

Processing

Parallel

Sequential

Speed

Very fast

Slower

Cost

Cheaper

Costly

Materials used

Non-toxic

Toxic

Size Data capacity

Very small Very large

Large Smaller

Miniaturization

Features Capability Flexibility

DNA COMPUTER

SILICON COMPUTER

Highly Complex Complex computations computations Less Good

Raw material Grows requirement exponentially

Remains stable

Energy Very negligible consumption

Comparatively higher

Control systems for chemical and biological processes Gene validation Lithography for nanotechnology and semiconductor applications Food traceability and safety DNA chips Study of logic Encryption of data for security Genetic programming and algorithms Design of Bio-chips Pharmaceutical applications Airline and communication routing Cracking of coded messages

1.news.nationalgeographic.com/ news/2003/02/0224_030224_ DNAcomputer.html - 38k 2.www.cnn.com 3. http://www.wisegeek.com/what-is-a-dna-computer.htm 4. http://www.tpgi.com.au/users/aoaug/dna_comp.html 5.http://www.sciam.com/article.cfm?articleID=000A4F2E-781B-1E5AA98A809EC5880105 6. http://unisci.com/stories/20021/0315023.htm 7.www.howstuffworks.com 8.www.bbcworld.com 9.www.wikipedia.com 10.Bio spectrum magazine-January 2006 11.DIGIT magazine-November 2005