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History Of PCR
:''(This article assumes familiarity with the terms and components used in the PCR process.)'' The history of the polymerase chain reaction (PCR) has variously been described as a classic Eureka (word), "Eureka!" moment, or as an example of cooperative teamwork between disparate researchers. Following is a list of events before, during, and after its development: Prelude * On April 25, 1953 James D. Watson and Francis Crick published "a radically different structure" for DNA, thereby founding the field of molecular genetics. Their Molecular structure of Nucleic Acids, structural model featured two strands of Complementarity (molecular biology), complementary Base pair, base-paired DNA, running in opposite directions as a double helix. They concluded their report saying that "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material". For this insight they were awarded the Nobel Priz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-strand Binding Protein
Single-strand DNA-binding protein (SSB) is a protein found in ''Escherichia coli'' (''E. coli'') bacteria, that binds to single-stranded regions of deoxyribonucleic acid ( DNA). Single-stranded DNA is produced during all aspects of DNA metabolism: replication, recombination, and repair. As well as stabilizing this single-stranded DNA, SSB proteins bind to and modulate the function of numerous proteins involved in all of these processes. Active ''E. coli'' SSB is composed of four identical 19 kDa subunits. Binding of single-stranded DNA to the tetramer can occur in different "modes", with SSB occupying different numbers of DNA bases depending on a number of factors, including salt concentration. For example, the (SSB)65 binding mode, in which approximately 65 nucleotides of DNA wrap around the SSB tetramer and contact all four of its subunits, is favoured at high salt concentrations ''in vitro''. At lower salt concentrations, the (SSB)35 binding mode, in which about 35 nucleotides bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone National Park
Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowstone National Park Protection Act and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the U.S. and is also widely held to be the first national park in the world. The park is known for its wildlife and its many geothermal features, especially the Old Faithful geyser, one of its most popular. While it represents many types of biomes, the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion. While Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust. In either case, the ultimate source of the heat is radioactive decay of naturally occurring radioactive elements in the Earth's mantle, the layer beneath the crust. Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with a pH as low as 0.8, to alkaline chloride springs saturated with silica, to bicarbonate springs saturated with carbon dioxide and carbonate minerals. Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of extremophiles, microorganisms adapted to extreme conditions, and it is possible that life on Earth had its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas D
Son Goku was a German rock band who played a mix of hardcore punk, alternative, reggae, and electronic sounds. The band was named after the Son Goku character in the ''Dragon Ball'' series. Son Goku's first and only album, ''Crashkurs'' (Crash course), was released in 2002 and reached a peak position of 15 on the Media Control Charts. The group has since disbanded due to "dissension" amongst the members. History Origins Son Goku was a side project of Thomas D of Die Fantastischen Vier. The band originated from the M.A.R.S. (Moderne Anstalt Rigoroser Spakker, or ''Modern Institute of Adamant Spakkers''), a commune of artists and musicians founded by Thomas D in 1998. Thomas D named the band after Son Goku, the protagonist of the ''Dragon Ball'' animated series, as the character embodied the band's philosophy; he stated he was "fascinated by Goku's naïveté and cheerfulness, yet, at the same time, a great warrior saving the world". Music Son Goku was formed with the "desire fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligonucleotide
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules. Oligonucleotides are characterized by the sequence of nucleotide residues that make up the entire molecule. The length of the oligonucleotide is usually denoted by " -mer" (from Greek ''meros'', "part"). For example, an oligonucleotide of six nucleotides (nt) is a hexamer, while one of 25 nt wou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligonucleotide Synthesis
Oligonucleotide synthesis is the chemical synthesis of relatively short fragments of nucleic acids with defined chemical structure (sequence). The technique is extremely useful in current laboratory practice because it provides a rapid and inexpensive access to custom-made oligonucleotides of the desired sequence. Whereas enzymes synthesize DNA and RNA only in a 5' to 3' direction, chemical oligonucleotide synthesis does not have this limitation, although it is most often carried out in the opposite, 3' to 5' direction. Currently, the process is implemented as solid-phase synthesis using phosphoramidite method and phosphoramidite building blocks derived from protected 2'-deoxynucleosides ( dA, dC, dG, and T), ribonucleosides ( A, C, G, and U), or chemically modified nucleosides, e.g. LNA or BNA. To obtain the desired oligonucleotide, the building blocks are sequentially coupled to the growing oligonucleotide chain in the order required by the sequence of the product (see ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Synthesis
Artificial gene synthesis, or simply gene synthesis, refers to a group of methods that are used in synthetic biology to construct and assemble genes from nucleotides '' de novo''. Unlike DNA synthesis in living cells, artificial gene synthesis does not require template DNA, allowing virtually any DNA sequence to be synthesized in the laboratory. It comprises two main steps, the first of which is solid-phase DNA synthesis, sometimes known as DNA printing. This produces oligonucleotide fragments that are generally under 200 base pairs. The second step then involves connecting these oligonucleotide fragments using various DNA assembly methods. Because artificial gene synthesis does not require template DNA, it is theoretically possible to make a completely synthetic DNA molecule with no limits on the nucleotide sequence or size. Synthesis of the first complete gene, a yeast tRNA, was demonstrated by Har Gobind Khorana and coworkers in 1972. Synthesis of the first peptide- and protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Code
The genetic code is the set of rules used by living cells to translate information encoded within genetic material ( DNA or RNA sequences of nucleotide triplets, or codons) into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries. The codons specify which amino acid will be added next during protein biosynthesis. With some exceptions, a three-nucleotide codon in a nucleic acid sequence specifies a single amino acid. The vast majority of genes are encoded with a single scheme (see the RNA codon table). That scheme is often referred to as the canonical or standard genetic code, or simply ''the'' genetic code, though variant codes (such as in mitochondria) exist. History Effor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Ligase
DNA ligase is a specific type of enzyme, a ligase, () that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond. It plays a role in repairing single-strand breaks in duplex DNA in living organisms, but some forms (such as DNA ligase IV) may specifically repair double-strand breaks (i.e. a break in both complementary strands of DNA). Single-strand breaks are repaired by DNA ligase using the complementary strand of the double helix as a template, with DNA ligase creating the final phosphodiester bond to fully repair the DNA. DNA ligase is used in both DNA repair and DNA replication (see '' Mammalian ligases''). In addition, DNA ligase has extensive use in molecular biology laboratories for recombinant DNA experiments (see '' Research applications''). Purified DNA ligase is used in gene cloning to join DNA molecules together to form recombinant DNA. Enzymatic mechanism The mechanism of DNA ligase is to form two covalent phos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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