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Reverse Transcription Polymerase Chain Reaction
Reverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA (in this context called complementary DNA or cDNA) and amplification of specific DNA targets using polymerase chain reaction (PCR). It is primarily used to measure the amount of a specific RNA. This is achieved by monitoring the amplification reaction using fluorescence, a technique called real-time PCR or quantitative PCR (qPCR). Confusion can arise because some authors use the acronym RT-PCR to denote real-time PCR. In this article, RT-PCR will denote Reverse Transcription PCR. Combined RT-PCR and qPCR are routinely used for analysis of gene expression and quantification of viral RNA in research and clinical settings. The close association between RT-PCR and qPCR has led to metonymic use of the term qPCR to mean RT-PCR. Such use may be confusing, as RT-PCR can be used without qPCR, for example to enable molecular cloning, sequencing or simple det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorimager
Photostimulated luminescence (PSL) is the release of stored energy within a phosphor by stimulation with visible light, to produce a luminescent signal. X-rays may induce such an energy storage. A plate based on this mechanism is called a photostimulable phosphor (PSP) plate (or imaging plate) and is one type of X-ray detector used in projectional radiography. Creating an image requires illuminating the plate twice: the first exposure, to the radiation of interest, "writes" the image, and a later, second illumination (typically by a visible-wavelength laser) "reads" the image. The device to read such a plate is known as a phosphorimager (occasionally spelled phosphoimager, perhaps reflecting its common application in molecular biology for detecting radiolabeled phosphorylated proteins and nucleic acids). Projectional radiography using a photostimulable phosphor plate as an X-ray detector can be called "phosphor plate radiography" or "computed radiography" (not to be confused with c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus-32
Phosphorus-32 (32P) is a radioactive isotope of phosphorus. The nucleus of phosphorus-32 contains 15 protons and 17 neutrons, one more neutron than the most common isotope of phosphorus, phosphorus-31. Phosphorus-32 only exists in small quantities on Earth as it has a short half-life of 14 days and so decays rapidly. Phosphorus is found in many organic molecules, and so, phosphorus-32 has many applications in medicine, biochemistry, and molecular biology where it can be used to trace phosphorylated molecules (for example, in elucidating metabolic pathways) and radioactively label DNA and RNA. Decay Phosphorus-32 has a short half-life of 14.268 days and decays into sulfur-32 by beta decay as shown in this nuclear equation: : 1.709 MeV of energy is released from this decay. The kinetic energy of the electron varies with an average of approximately 0.5 MeV and the remainder of the energy is carried by the nearly undetectable electron antineutrino. In comparison to oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethidium Bromide
Ethidium bromide (or homidium bromide, chloride salt homidium chloride) is an intercalating agent commonly used as a fluorescent tag (nucleic acid stain) in molecular biology laboratories for techniques such as agarose gel electrophoresis. It is commonly abbreviated as EtBr, which is also an abbreviation for bromoethane. To avoid confusion, some laboratories have used the abbreviation EthBr for this salt. When exposed to ultraviolet light, it will fluoresce with an orange colour, intensifying almost 20-fold after binding to DNA. Under the name homidium, it has been commonly used since the 1950s in veterinary medicine to treat trypanosomiasis in cattle. The high incidence of antimicrobial resistance makes this treatment impractical in some areas, where the related isometamidium chloride is used instead. Despite its reputation as a mutagen, tests have shown it to have low mutagenicity without metabolic activation. Structure, chemistry, and fluorescence As with most fluoresc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state of matter, state from solid to liquid. At the melting point the solid and liquid phase (matter), phase exist in Thermodynamic equilibrium, equilibrium. The melting point of a substance depends on pressure and is usually specified at a Standard temperature and pressure, standard pressure such as 1 Atmosphere (unit), atmosphere or 100 Pascal (unit), kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to Supercooling, supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the #Melting point measurements, melting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SYBR Green
SYBR Green I (SG) is an asymmetrical cyanine dye used as a nucleic acid stain in molecular biology. The SYBR family of dyes is produced by Molecular Probes Inc., now owned by Thermo Fisher Scientific. SYBR Green I binds to DNA. The resulting DNA-dye-complex best absorbs 497 nanometer blue light (λmax = 497 nm) and emits green light (λmax = 520 nm). The stain preferentially binds to double-stranded DNA, but will stain single-stranded (ss) DNA with lower performance. SYBR Green can also stain RNA with a lower performance than ssDNA. Uses SYBR Green finds usage in several areas of biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ... and molecular biology. It is used as a dye for the quantification of double stranded DNA in some methods of quantitative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serum (blood)
Serum () is the fluid and solvent component of blood which does not play a role in clotting. It may be defined as blood plasma without the clotting factors, or as blood with all cells and clotting factors removed. Serum contains all proteins except clotting factors (involved in blood clotting), including all electrolytes, antibodies, antigens, hormones; and any exogenous substances (e.g., drugs, microorganisms). Serum also does not contain all the formed elements of blood, which include blood cells, white blood cells ( leukocytes, lymphocytes), red blood cells ( erythrocytes), and platelets. The study of serum is serology. Serum is used in numerous diagnostic tests as well as blood typing. Measuring the concentration of various molecules can be useful for many applications, such as determining the therapeutic index of a drug candidate in a clinical trial. To obtain serum, a blood sample is allowed to clot ( coagulation). The sample is then centrifuged to remove th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whole Blood
Whole blood (WB) is human blood from a standard blood donation. It is used in the treatment of massive bleeding, in exchange transfusion, and when people donate blood to themselves (autologous transfusion). One unit of whole blood (approximately 450 mL) increases hemoglobin levels by about 10 g/L. Cross matching is typically done before the blood is given. It is given by injection into a vein. Side effects include red blood cell breakdown, high blood potassium, infection, volume overload, lung injury, and allergic reactions such as anaphylaxis. Whole blood is made up of red blood cells, white blood cells, platelets, and blood plasma. It is best within a day of collection; however, it can be stored for up to three weeks if refrigerated (1-6 °C). The blood is typically combined with an anticoagulant and preservative during the collection process. The first transfusion of whole blood was in 1818; however, common use did not begin until the First and Second World ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermostable DNA Polymerase
Thermostable DNA polymerases are DNA polymerases that originate from thermophiles, usually bacterial or archaeal species, and are therefore thermostable. They are used for the polymerase chain reaction and related methods for the amplification and modification of DNA. Properties Several DNA polymerases have been described with distinct properties that define their specific utilisation in a PCR, in real-time PCR or in an isothermal amplification. Being DNA polymerases, the thermostable DNA polymerases all have a 5'→3' polymerase activity, and either a 5'→3' or a 3'→5' exonuclease activity. Structure DNA polymerases are roughly shaped like a hand with a thumb, palm and fingers.T. A. Steitz''DNA polymerases: structural diversity and common mechanisms.''In: '' Journal of Biological Chemistry.'' Volume 274, issue 25, June 1999, p. 17395–17398, , .P. J. Rothwell, G. Waksman: ''Structure and mechanism of DNA polymerases.'' In: ''Advances in protein chemistry.'' Volu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is created during the process of Transcription (biology), transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as Translation (biology), translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of geneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
