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DNA End
DNA ends refer to the properties of the ends of linear DNA molecules, which in molecular biology are described as "sticky" or "blunt" based on the shape of the complementary strands at the terminus. In sticky ends, one strand is longer than the other (typically by at least a few nucleotides), such that the longer strand has bases which are left unpaired. In blunt ends, both strands are of equal length – i.e. they end at the same base position, leaving no unpaired bases on either strand. The concept is used in molecular biology, in cloning, or when subcloning insert DNA into vector DNA. Such ends may be generated by restriction enzymes that break the molecule's phosphodiester backbone at specific locations, which themselves belong to a larger class of enzymes called exonucleases and endonucleases. A restriction enzyme that cuts the backbones of both strands at non-adjacent locations leaves a staggered cut, generating two overlapping sticky ends, while an enzyme that makes a str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactions. Though cells and other microscopic structures had been observed in living organisms as early as the 18th century, a detailed understanding of the mechanisms and interactions governing their behavior did not emerge until the 20th century, when technologies used in physics and chemistry had advanced sufficiently to permit their application in the biological sciences. The term 'molecular biology' was first used in 1945 by the English physicist William Astbury, who described it as an approach focused on discerning the underpinnings of biological phenomena—i.e. uncovering the physical and chemical structures and properties of biological molecules, as well as their interactions with other molecules and how these interactions explain observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymine
Thymine () (symbol T or Thy) is one of the four nucleotide bases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. In RNA, thymine is replaced by the nucleobase uracil. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calf thymus glands, hence its name. Derivation As its alternate name (5-methyluracil) suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA, thymine is replaced with uracil in most cases. In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures. Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine. Thymidine can be phosphorylated with up to three phosphoric acid groups, producing dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Spring Harbor Laboratory Press
Cold Spring Harbor Laboratory Press was founded in 1933 to aid in Cold Spring Harbor Laboratory's purpose of furthering the advance and spread of scientific knowledge. CSHL Press publishes monographs, technical manuals, handbooks, review volumes, conference proceedings, scholarly journals and videotapes. These examine important topics in molecular biology, genetics, development, virology, neurobiology, immunology and cancer biology. Manuscripts for books and for journal publication are invited from scientists worldwide. Revenue from sales of CSHL Press publications is used solely in support of research at Cold Spring Harbor Laboratory. Journals Scientific journals published by CSHL Press: * ''Cold Spring Harbor Molecular Case Studies'' * ''Cold Spring Harbor Perspectives in Biology'' * ''Cold Spring Harbor Perspectives in Medicine'' * '' Cold Spring Harbor Protocols'' * '' Cold Spring Harbor Symposia on Quantitative Biology'' * ''Genes & Development'' * ''Genome Research'' * ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sambrook, Joseph
Joseph Frank Sambrook (1 March 1939 – 14 June 2019) was a British molecular biologist known for his studies of DNA oncoviruses and the molecular biology of normal and cancerous cells. Education and early career Sambrook was educated at the University of Liverpool (BSc (hons) 1962) and obtained his Doctor of Philosophy, PhD at the Australian National University in 1966. He did postdoctoral research at the Medical Research Council (UK), MRC Laboratory of Molecular Biology (1966–67) and the Salk Institute for Biological Studies (1967–69). In 1969 he was hired by James D. Watson to work at the Cold Spring Harbor Laboratory in New York (state), New York. Watson has been reported to say this was the best hiring decision he ever made. Joe was responsible for creating a combative creative environment at CSHL that fomented discovery. Subsequently, he worked at the University of Texas Southwestern Medical Center (Dallas). Achievements Sambrook is best known for his studies on DN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endonuclease
In molecular biology, endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain (namely DNA or RNA). Some, such as deoxyribonuclease I, cut DNA relatively nonspecifically (with regard to sequence), while many, typically called '' restriction endonucleases'' or ''restriction enzymes'', cleave only at very specific nucleotide sequences. Endonucleases differ from exonucleases, which cleave the ends of recognition sequences instead of the middle (''endo'') portion. Some enzymes known as "exo-endonucleases", however, are not limited to either nuclease function, displaying qualities that are both endo- and exo-like. Evidence suggests that endonuclease activity experiences a lag compared to exonuclease activity. Restriction enzymes are endonucleases from eubacteria and archaea that recognize a specific DNA sequence. The nucleotide sequence recognized for cleavage by a restriction enzyme is called the ''restriction site''. Typically, a restriction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EcoRI
EcoRI (pronounced "eco R one") is a restriction endonuclease enzyme isolated from species '' E. coli.'' It is a restriction enzyme that cleaves DNA double helices into fragments at specific sites, and is also a part of the restriction modification system. The ''Eco'' part of the enzyme's name originates from the species from which it was isolated"E" denotes generic name, "Escherichia", and "co" denotes species name, "coli"while the R represents the particular strain, in this case RY13, and the I denotes that it was the first enzyme isolated from this strain. In molecular biology it is used as a restriction enzyme. EcoRI creates 4 nucleotide sticky ends with 5' end overhangs of AATT. The nucleic acid recognition sequence where the enzyme cuts is G↓AATTC, which has a palindromic complementary sequence of CTTAA↓G. Other restriction enzymes, depending on their cut sites, can also leave 3' overhangs or blunt ends with no overhangs. History EcoRI is an example of type II restrict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronald W
Ronald is a masculine given name derived from the Old Norse ''Rögnvaldr'', Hanks; Hardcastle; Hodges (2006) p. 234; Hanks; Hodges (2003) § Ronald. or possibly from Old English '' Regenweald''. In some cases ''Ronald'' is an Anglicised form of the Gaelic '' Raghnall'', a name likewise derived from ''Rögnvaldr''. The latter name is composed of the Old Norse elements ''regin'' ("advice", "decision") and ''valdr'' ("ruler"). ''Ronald'' was originally used in England and Scotland, where Scandinavian influences were once substantial, although now the name is common throughout the English-speaking world. A short form of ''Ronald'' is ''Ron''. Pet forms of ''Ronald'' include ''Roni'' and '' Ronnie''. ''Ronalda'' and ''Rhonda'' are feminine forms of ''Ronald''. ''Rhona'', a modern name apparently only dating back to the late nineteenth century, may have originated as a feminine form of ''Ronald''. Hanks; Hardcastle; Hodges (2006) pp. 230, 408; Hanks; Hodges (2003) § Rhona. The names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanine
Guanine () (symbol G or Gua) is one of the four main nucleotide bases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine ( uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called guanosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine- imidazole ring system with conjugated double bonds. This unsaturated arrangement means the bicyclic molecule is planar. Properties Guanine, along with adenine and cytosine, is present in both DNA and RNA, whereas thymine is usually seen only in DNA, and uracil only in RNA. Guanine has multiple tautomeric forms. For the imidazole ring, the proton can reside on either nitrogen. For the pyrimidine ring, the ring N-H can center can reside on either of the ring nitrogens. The latter tautomer does not apply to nucleoside or nucleotide versions of guanine. It binds to cytosine through three hydrogen bonds. In cytosine, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosine
Cytosine () (symbol C or Cyt) is one of the four nucleotide bases found in DNA and RNA, along with adenine, guanine, and thymine ( uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at position 2). The nucleoside of cytosine is cytidine. In Watson–Crick base pairing, it forms three hydrogen bonds with guanine. History Cytosine was discovered and named by Albrecht Kossel and Albert Neumann in 1894 when it was hydrolyzed from calf thymus tissues. A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year. In 1998, cytosine was used in an early demonstration of quantum information processing when Oxford University researchers implemented the Deutsch–Jozsa algorithm on a two qubit nuclear magnetic resonance quantum computer (NMRQC). In March 2015, NASA scientists reported the formation of cytosine, alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restriction Endonucleases
A restriction enzyme, restriction endonuclease, REase, ENase or'' restrictase '' is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class of the broader endonuclease group of enzymes. Restriction enzymes are commonly classified into five types, which differ in their structure and whether they cut their DNA substrate at their recognition site, or if the recognition and cleavage sites are separate from one another. To cut DNA, all restriction enzymes make two incisions, once through each sugar-phosphate backbone (i.e. each strand) of the DNA double helix. These enzymes are found in bacteria and archaea and provide a defense mechanism against invading viruses. Inside a prokaryote, the restriction enzymes selectively cut up ''foreign'' DNA in a process called ''restriction digestion''; meanwhile, host DNA is protected by a modification enzyme (a methyltransferase) that modifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study. PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation. Mullis and biochemist Michael Smith (chemist), Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993. PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of Ancient DNA, ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
