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For other uses, see DNA (disambiguation).
For a non-technical introduction to the topic, see Introduction to genetics.
The structure of part of a DNA double helix
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules […]
The origins of Madison’s technology industry can be traced back much farther than 1982, but Fred Blattner felt pretty isolated when he opened DNASTAR, Inc. that year.
Other than another young company - an upstart called Promega - and a few more, the producer of DNA analysis software was in need of companionship. The early 1980s […]
Structural proteins that bind DNA are well-understood examples of non-specific DNA-protein interactions. Within chromosomes, DNA is held in complexes with structural proteins. These proteins organize the DNA into a compact structure called chromatin. In eukaryotes this structure involves DNA binding to a complex of small basic proteins called histones, while in prokaryotes multiple types of […]
DNA polymerases are a family of enzymes critical for all forms of DNA replication. A DNA polymerase synthesizes a new strand of DNA by extending the 3′ end of an existing nucleotide chain, adding new nucleotides matched to the template strand one at a time. Some DNA polymerases may also have some proofreading ability, removing […]
DNA is a long polymer made from repeating units called nucleotides. The DNA chain is 22 to 26 Ã…ngströms wide (2.2 to 2.6 nanometres), and one nucleotide unit is 3.3 Ã… (0.33 nm) long. Although each individual repeating unit is very small, DNA polymers can be enormous molecules containing millions of nucleotides. For instance, the […]
The double helix is a right-handed spiral. As the DNA strands wind around each other, they leave gaps between each set of phosphate backbones, revealing the sides of the bases inside (see animation). There are two of these grooves twisting around the surface of the double helix: one groove, the major groove, is 22 Ã… […]
Each type of base on one strand forms a bond with just one type of base on the other strand. This is called complementary base pairing. Here, purines form hydrogen bonds to pyrimidines, with A bonding only to T, and C bonding only to G. This arrangement of two nucleotides binding together across the double […]
Welcome to DNA Identifiers’ Mobile & Clinical DNA, Paternity & Immigration Testing Services!
DNA and Paternity Testing… Boy, there sure is a lot of conflicting information available online and it can be difficult to sort it all out! Most people have common concerns and questions when researching a test, such as:
Can’t I just order a DNA […]
Scientist use the term “double helix” to describe DNA’s winding, two-stranded chemical structure. This shape - which looks much like a twisted ladder - gives DNA the power to pass along biological instructions with great precision.
To understand DNA’s double helix from a chemical standpoint, picture the sides of the ladder as strands of alternating sugar […]
Eukaryotes (cells with nuclei such as plants, yeast, and animals) possess multiple large linear chromosomes contained in the cell’s nucleus. Each chromosome has one centromere, with one or two arms projecting from the centromere, although under most circumstances these arms are not visible as such. In addition most eukaryotes have a small circular mitochondrial genome, […]
