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Delitto Perfetto
''Delitto perfetto'' ({{IPA-it, deˈlitto perˈfɛtto, lang) is a genetic technique for ''in vivo'' site-directed mutagenesis in yeast. This name is the Italian term for "perfect murder", and it refers to the ability of the technique to create desired genetic changes without leaving any foreign DNA in the genome. Background This technique was developed by a group at the National Institute of Environmental Health Sciences (NIEHS) composed of Michael A. Resnick, Francesca Storici (now at Georgia Institute of Technology), and L. Kevin Lewis (now at Southwest Texas State University). The method uses synthetic oligonucleotides in combination with the cellular process of homologous recombination. Consequently, it is well suited for genetic manipulation of yeast, which has highly efficient homologous recombination. The ''delitto perfetto'' approach has been used to produce single and multiple point mutations, gene truncations or insertions, and whole gene deletions (including essential ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Site-directed Mutagenesis
Site-directed mutagenesis is a molecular biology method that is used to make specific and intentional mutating changes to the DNA sequence of a gene and any gene products. Also called site-specific mutagenesis or oligonucleotide-directed mutagenesis, it is used for investigating the structure and biological activity of DNA, RNA, and protein molecules, and for protein engineering. Site-directed mutagenesis is one of the most important laboratory techniques for creating DNA libraries by introducing mutations into DNA sequences. There are numerous methods for achieving site-directed mutagenesis, but with decreasing costs of oligonucleotide synthesis, artificial gene synthesis is now occasionally used as an alternative to site-directed mutagenesis. Since 2013, the development of the CRISPR/Cas9 technology, based on a prokaryotic viral defense system, has also allowed for the editing of the genome, and mutagenesis may be performed ''in vivo'' with relative ease. History Early attempt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassettes
Cassette may refer to: Technology * Cassette tape (or ''musicassette'', ''audio cassette'', ''cassette tape'', or ''tape''), a worldwide standard for analog audio recording and playback ** Cassette single (or "Cassingle"), a music single in the form of a cassette tape * Digital Audio Tape (or ''DAT''), a digital audio cassette tape format, mainly used by professionals * Digital Compact Cassette (or ''DCC''), a short-lived digital audio cassette format aimed at domestic users * Videocassette, a cassette containing videotape, for use in VCRs * Data cassette, the magnetic tape in plastic housing Music * ''Album'' (Public Image Ltd album), a 1986 Public Image Ltd album called "Cassette" on certain editions * Cassette (New Zealand band), a band from New Zealand * Cassette (South African band), a band from South Africa * The Cassettes, a Washington, DC based "Mystic Country"/Steampunk band formed in 1999 * Cassette (Romania), a band from Romania People * Benny Cassette, American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italian Words And Phrases
Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Italian, regional variants of the Italian language ** Languages of Italy, languages and dialects spoken in Italy ** Italian culture, cultural features of Italy ** Italian cuisine, traditional foods ** Folklore of Italy, the folklore and urban legends of Italy ** Mythology of Italy, traditional religion and beliefs Other uses * Italian dressing, a vinaigrette-type salad dressing or marinade * Italian or Italian-A, alternative names for the Ping-Pong virus, an extinct computer virus See also * * * Italia (other) * Italic (other) * Italo (other) * The Italian (other) * Italian people (other) Italian people may refer to: * in terms of ethnicity: all ethnic Italians, in and outside of Italy * in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs). This can eventually lead to malignant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) to a large enough amount to study in detail. PCR was invented in 1983 by the 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Restriction Enzyme
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] |
Galactose
Galactose (, '' galacto-'' + '' -ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule. Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates. D-Galactose is also known as brain sugar since it is a component of glycoproteins (oligosaccharide-protein compounds) found in Nerve tissue, nerve tissue. Etymology The word ''galactose'' was coined by Charles Weissman in the mid-19th century and is derived from Greek ''galaktos'' (of milk) and the generic chemical suffix for sugars ''-ose''. The etymology is comparable to that of the word '' lactose'' in that both contain roots meaning "milk sugar". Lactose is a disaccharide of galactose plus glucose. Structure and isomerism Gal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
URA3
URA3 is a gene on chromosome V in ''Saccharomyces cerevisiae'' (yeast). Its systematic name is YEL021W. URA3 is often used in yeast research as a "marker gene", that is, a gene to label chromosomes or plasmids. URA3 encodes Orotidine 5'-phosphate decarboxylase (ODCase), which is an enzyme that catalyzes one reaction in the synthesis of pyrimidine ribonucleotides (a component of RNA). Use in yeast research Loss of ODCase activity leads to a lack of cell growth unless uracil or uridine is added to the media. The presence of the URA3 gene in yeast restores ODCase activity, facilitating growth on media not supplemented with uracil or uridine, thereby allowing selection for yeast carrying the gene. In contrast, if 5-FOA (5-Fluoroorotic acid) is added to the media, the active ODCase will convert 5-FOA into the toxic compound (a suicide inhibitor) 5-fluorouracil causing cell death, which allows for selection against yeast carrying the gene. Since URA3 allows for both positive and nega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygromycin B
Hygromycin B is an antibiotic produced by the bacterium '' Streptomyces hygroscopicus''. It is an aminoglycoside that kills bacteria, fungi and higher eukaryotic cells by inhibiting protein synthesis. History Hygromycin B was originally developed in the 1950s for use with animals and is still added into swine and chicken feed as an anthelmintic or anti-worming agent (product name: Hygromix). Hygromycin B is produced by ''Streptomyces hygroscopicus'', a bacterium isolated in 1953 from a soil sample. Resistance genes were discovered in the early 1980s. Mechanism of action Hygromycin is active against both prokaryotic and eukaryotic cells. It acts by inhibiting polypeptide synthesis. It stabilizes the tRNA-ribosomal acceptor site, thereby inhibiting translation. Use in research In the laboratory it is used for the selection and maintenance of prokaryotic and eukaryotic cells that contain the hygromycin resistance gene. The resistance gene is a kinase that inactivates hygr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G418
G418 (Geneticin) is an aminoglycoside antibiotic similar in structure to gentamicin B1. It is produced by ''Micromonospora rhodorangea''. G418 blocks polypeptide synthesis by inhibiting the elongation step in both prokaryotic and eukaryotic cells. Resistance to G418 is conferred by the neo gene from Tn5 encoding an aminoglycoside 3'-phosphotransferase, APT 3' II. G418 is an analog of neomycin sulfate, and has similar mechanism as neomycin. G418 is commonly used in laboratory research to select genetically engineered cells . In general for bacteria and algae concentrations of 5 μg/mL or less are used, for mammalian cells concentrations of approximately 400 μg/mL are used for selection and 200 μg/mL for maintenance. However, optimal concentration for resistant clones selection in mammalian cells depends on the cell line used as well as on the plasmid carrying the resistance gene, therefore antibiotic titration should be done to find the best condition for every ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
