Defense Intelligence Reference Document Quantum Computing And Utilizing Organic Molecules In Automation Technology

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several nitrogen-containing bases consisting of deoxyribonucleic acid (DNA). By the late
1940s the scientific community widely accepted DNA as the carrier of genetic information.
But, it wasn't until 1977 that Fred Sanger developed the first dideoxynucleotide chain
termination bottom up assembly method for DNA. (84) This technique would later usher in a
new age of nucleic acid research and open the door for the modern era of biotechnology.
With the advent of the Polymerase Chain Reaction (PCR) (85) technology a virtual treasure
trove of capabilities now exist for genetic and biochemical engineers to create customized
DNA strands. This revolutionary process has created a multidisciplinary field of work within
nanotechnology that intersects at the crossroads of computer science, biochemistry, material
science, and engineering. This section on DNA-based nanosystems and computing will
introduce several state of the art research applications and concepts currently being
employed to produce DNA-based devices.
It is crucial to formulate a basic understanding of the structure and chemical principles of the
DNA molecule to fully grasp its potential as a building material for DNA-based nanosytems.
For the lay reader we have constructed a simplistic outline to illustrate the general principles
of the DNA molecule that hold true to their biochemical properties as they apply to bottom-
up nanostructure assemblies.
1. DNA consists of two long polymers made of simple units called nucleotides, with
backbones made of sugars and phosphate groups joined by ester bonds. These two
strands run in opposite directions to each other and are therefore anti-parallel. The
double strands of DNA form a double helical structure.
2. The information in DNA is stored as a code made up of four chemical bases: adenine (A),
guanine (G), cytosine (C), and thymine (T). The order, or sequence, of these bases
determines the information available for building and maintaining an organism. These
nucleotides bind through a chemical bonding process known as Watson and Crick base
pairing. A bonds with T, and G bonds with C - a given sequence of such nucleotides will
always bond with the complementary sequence.P
3. In its double helical configuration, DNA is a relatively rigid molecule. This rigidity can be
further enhanced by bundling several double helixes to form DNA lattices and tiles to
form synthesized nanoarchitechtures (87)(88)(89).
4. The Watson and Crick base-pairing principles have created predictable binding affinities in
bench top applications. This knowledge of the intra- and inter-molecular physical
properties of the DNA molecule enable the programming of desired interactions within the
sequences to produce a customized sequence of DNA.
5. The ease in sequencing DNA based on the Sanger technique, which today has evolved
into advanced automated processes, have made designer DNA strands readily available.
Customized strand lengths or oligonucleotides (strands typically 100-200 base pairs long)
can be easily ordered from various sequencing services or produced within the lab at
relatively low costs with high throughput and quality.
6. Today biotechnologists can employ a library of unique restriction enzymes that can cut
the DNA strand between specific nucleotides leaving "sticky ends", or single stranded
P Sometimes transcription errors will result in an incorrect bond, such as A with G. These are single nucleotide
polymorphisms, or SNPs (pronounced "snips"). SNPs are not uncommon in the human genome and have important
implications in disease; however, in the current treatise we consider such "wrong" pairings to be errors that need
correction.
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