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E. Coli K-12
''Escherichia coli'' (; commonly abbreviated ''E. coli'') is a Gram-negative gammaproteobacterium commonly found in the lower intestine of warm-blooded organisms (endotherms). The descendants of two isolates, K-12 and B strain, are used routinely in molecular biology as both a tool and a model organism. Diversity ''Escherichia coli'' is one of the most diverse bacterial species, with several pathogenic strains with different symptoms and with only 20% of the genome common to all strains. Furthermore, from the evolutionary point of view, the members of genus ''Shigella'' (''dysenteriae'', ''flexneri'', ''boydii'', ''sonnei'') are actually ''E. coli'' strains "in disguise" (i.e. ''E. coli'' is paraphyletic to the genus). History In 1885, Theodor Escherich, a German pediatrician, first discovered this species in the feces of healthy individuals and called it ''Bacterium coli commune'' because it is found in the colon and early classifications of Prokaryotes placed these in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacuu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martha Wollstein
Martha Wollstein (November 21, 1868 – September 30, 1939) was an American physician. Wollstein was born in New York to a German Jewish family. Biography Wollstein was educated at the Woman's Medical College of the New York Infirmary, which became part of the Cornell University Medical School in 1909. There she studied with Mary Corinna Putnam Jacobi, with whom she would later publish her first paper in 1902, on a myosarcoma of the uterus. After graduating in 1890, Wollstein joined the Babies Hospital in New York, where she became a pathologist in 1892. Her work there included research on infant diarrhea, malaria, tuberculosis, and typhoid fever. In 1904, she was invited by Simon Flexner to join the Rockefeller Institute for Medical Research as an assistant researcher, though she continued to work at the Babies Hospital even after this. At the Rockefeller Institute she did experimental work on polio, studied pneumonia, and helped to develop an antimeningitis serum. In a stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells. In these tissues the absorbed glucose is converted into either glycogen via glycogenesis or fats (triglycerides) via lipogenesis, or, in the case of the liver, into both. Glucose production and secretion by the liver is strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is therefore an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules inside the cells. Low insulin levels in the blood have the opposite effect by promoting widespread catabolism, especially o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinant Proteins
Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome. Recombinant DNA is the general name for a piece of DNA that has been created by combining at least two fragments from two different sources. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure, and differ only in the nucleotide sequence within that identical overall structure. Recombinant DNA molecules are sometimes called chimeric DNA, because they can be made of material from two different species, like the mythical chimera. R-DNA technology uses palindromic sequences and leads to the production of sticky and blunt ends. The DNA sequences used in the construction of recombinant DNA molecules can originate from any species. For example, plant DNA may be joined to bacter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Fermentation
Industrial fermentation is the intentional use of fermentation in manufacturing products useful to humans. In addition to the mass production of fermented foods and drinks, industrial fermentation has widespread applications in chemical industry. Commodity chemicals, such as acetic acid, citric acid, and ethanol are made by fermentation. Moreover, nearly all commercially produced industrial enzymes, such as lipase, invertase and rennet, are made by fermentation with genetically modified microbes. In some cases, production of biomass itself is the objective, as is the case for single-cell proteins, baker's yeast, and starter cultures for lactic acid bacteria used in cheesemaking. In general, fermentations can be divided into four types: * Production of biomass (viable cellular material) * Production of extracellular metabolites (chemical compounds) * Production of intracellular components (enzymes and other proteins) * Transformation of substrate (in which the transformed sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterologous
The term heterologous has several meanings in biology. Gene expression In cell biology and protein biochemistry, heterologous expression means that a protein is experimentally put into a cell that does not normally make (i.e., express) that protein. Heterologous (meaning 'derived from a different organism') refers to the fact that often the transferred protein was initially cloned from or derived from a different cell type or a different species from the recipient. Typically the protein itself is not transferred, but instead the 'correctly edited' genetic material coding for the protein (the complementary DNA or cDNA) is added to the recipient cell. The genetic material that is transferred typically must be within a format that encourages the recipient cell to express the cDNA as a protein (i.e., it is put in an expression vector). Methods for transferring foreign genetic material into a recipient cell include transfection and transduction. The choice of recipient cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinant DNA
Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome. Recombinant DNA is the general name for a piece of DNA that has been created by combining at least two fragments from two different sources. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure, and differ only in the nucleotide sequence within that identical overall structure. Recombinant DNA molecules are sometimes called chimeric DNA, because they can be made of material from two different species, like the mythical chimera. R-DNA technology uses palindromic sequences and leads to the production of sticky and blunt ends. The DNA sequences used in the construction of recombinant DNA molecules can originate from any species. For example, plant DNA may be joined to bacter ... [...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] |
Plasmid
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that benefit the survival of the organism and confer selective advantage such as antibiotic resistance. While chromosomes are large and contain all the essential genetic information for living under normal conditions, plasmids are usually very small and contain only additional genes that may be useful in certain situations or conditions. Artificial plasmids are widely used as vectors in molecular cloning, serving to drive the replication of recombinant DNA sequences within host organisms. In the laboratory, plasmids may be introduced into a cell via transformation. Synthetic plasmids are available for procurement over the inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert Boyer
Herbert Wayne "Herb" Boyer (born July 10, 1936) is an American biotechnologist, researcher and entrepreneur in biotechnology. Along with Stanley N. Cohen and Paul Berg he discovered a method to coax bacteria into producing foreign proteins, thereby jump-starting the field of genetic engineering. By 1969, he performed studies on a couple of restriction enzymes of the E.coli bacterium with especially useful properties. He is recipient of the 1990 National Medal of Science, co-recipient of the 1996 Lemelson–MIT Prize, and a co-founder of Genentech. He was professor at the University of California, San Francisco (UCSF) and later served as vice president of Genentech from 1976 until his retirement in 1991. Life and career Herbert Boyer was born in 1936 in Derry, Pennsylvania. He received his bachelor's degree in biology and chemistry from Saint Vincent College in Latrobe, Pennsylvania, in 1958. He married his wife Grace the following year. He received his PhD at the University of P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanley Norman Cohen
Stanley Norman Cohen (born February 17, 1935) is an American geneticist and the Kwoh-Ting Li Professor in the Stanford University School of Medicine. Stanley Cohen and Herbert Boyer were the first scientists to transplant genes from one living organism to another, a fundamental discovery for genetical engineering. Thousands of products have been developed on the basis of their work, including human growth hormone and hepatitis B vaccine. According to immunologist Hugh McDevitt, "Cohen's DNA cloning technology has helped biologists in virtually every field". Without it, "the face of biomedicine and biotechnology would look totally different." Boyer cofounded Genentech in 1976 based on their work together, but Cohen was a consultant for Cetus Corporation and declined to join. Early life Cohen was born in Perth Amboy, New Jersey. He graduated from Rutgers University with a B.S. in 1956, and received his M.D. from the University of Pennsylvania School of Medicine in 1960. Cohen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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