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Bromophenol Blue
Bromophenol blue (3′,3″,5′,5″-tetrabromophenolsulfonphthalein, BPB), albutest is used as a pH indicator, an electrophoretic color marker, and a dye. It can be prepared by slowly adding excess bromine to a hot solution of phenolsulfonphthalein in glacial acetic acid. Acid–base indicator As an acid–base indicator, its useful range lies between pH 3.0 and 4.6. It changes from yellow at pH 3.0 to blue at pH 4.6; this reaction is reversible. Bromophenol blue is structurally related to phenolphthalein (a popular indicator). Color marker Bromophenol is also used as a colour marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Since bromophenol blue carries a slight negative charge at moderate pH, it will migrate in the same direction as DNA or protein in a gel; the rate at which it migrates varies according to gel density and buffer composition, but in a typical 1% agarose gel in a 1X TAE buffer or TBE buff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PH Indicator
A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, a pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+) in the Arrhenius model. Normally, the indicator causes the color of the solution to change depending on the pH. Indicators can also show change in other physical properties; for example, olfactory indicators show change in their odor. The pH value of a neutral solution is 7.0 at 25°C ( standard laboratory conditions). Solutions with a pH value below 7.0 are considered acidic and solutions with pH value above 7.0 are basic. Since most naturally occurring organic compounds are weak electrolytes, such as carboxylic acids and amines, pH indicators find many applications in biology and analytical chemistry. Moreover, pH indicators form one of the three main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (or "Watson–Crick–Franklin") base pairs (guanine–cytosine and adenine–thymine) allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The Complementarity (molecular biology), complementary nature of this based-paired structure provides a redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and RNA polymerase transcribes DNA in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenol Dyes
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it requires careful handling because it can cause chemical burns. Phenol was first extracted from coal tar, but today is produced on a large scale (about 7 billion kg/year) from petroleum-derived feedstocks. It is an important industrial commodity as a precursor to many materials and useful compounds. It is primarily used to synthesize plastics and related materials. Phenol and its chemical derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides, and numerous pharmaceutical drugs. Properties Phenol is an organic compound appreciably soluble in water, with about 84.2 g dissolving in 1000 mL (0.895 M). Homogeneous mixtures of phenol and water at phenol to wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PH Indicators
A pH indicator is a halochromism, halochromic chemical compound added in small amounts to a Solution (chemistry), solution so the pH (acidity or Base (chemistry), basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, a pH indicator is a Chemical substance, chemical detector for hydronium ions (H3O+) or hydrogen ions (H+) in the Acid-base reaction theories, Arrhenius model. Normally, the indicator causes the color of the solution to change depending on the pH. Indicators can also show change in other physical properties; for example, olfactory indicators show change in their odor. The pH value of a neutral solution is 7.0 at 25°C (Standard_conditions_for_temperature_and_pressure#Standard_laboratory_conditions, standard laboratory conditions). Solutions with a pH value below 7.0 are considered acidic and solutions with pH value above 7.0 are basic. Since most naturally occurring Organic compound, organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromophenol
A bromophenol is any organobromide of phenol that contains one or more covalently bonded bromine atoms. There are five basic types of bromophenols (mono- to pentabromophenol) and 19 different bromophenols in total when positional isomerism is taken into account. Bromophenols are produced by electrophilic halogenation of phenol with bromine. List of bromophenols There is a total of 19 bromophenols, corresponding to the different ways in which bromine atoms can be attached to the five carbon atoms in the benzene ring of the phenol molecule, excluding the carbon atom to which the hydroxy group is attached. Monobromrophenols have three isomers because there is only one bromine atom that can occupy one of three ring positions on the phenol molecule; 2-bromophenol, for example, is the isomer that has a bromine atom in the '' ortho'' position. Pentabromophenol, by contrast, has only one isomer because all five available ring positions on the phenol are fully brominated. * Monobro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kreft's Dichromaticity Index
Kreft's dichromaticity index (DI) is a measure for quantification of dichromatism. It is defined as the difference in hue angle (Δhab) between the color of the sample at the dilution, where the chroma (color saturation) is maximal, and the color of four times more diluted (or thinner) and four times more concentrated (or thicker) sample. The two hue angle differences are called the dichromaticity index towards lighter (Kreft's DIL) and dichromaticity index towards darker (Kreft's DID) respectively. Kreft's dichromaticity indexes DIL and DID for pumpkin seed oil, which is one of the most dichromatic substances, are −9 and −44, respectively. This means, that pumpkin seed oil changes its color from green-yellow to orange-red (for 44 degrees in Lab color space) when the thickness of the observed layer is increased from cca 0.5 mm to 2 mm; and it changes slightly towards green (for 9 degrees) if its thickness is reduced for four-fold. The color of pumpkin oil at increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichromatism
Dichromatism (or polychromatism) is a phenomenon where a material or solution's hue is dependent on both the concentration of the absorbing substance and the depth or thickness of the medium traversed. In most substances which are not dichromatic, only the brightness and saturation of the colour depend on their concentration and layer thickness. Examples of dichromatic substances are pumpkin seed oil, bromophenol blue, and resazurin. When the layer of pumpkin seed oil is less than 0.7 mm thick, the oil appears bright green, and in layer thicker than this, it appears bright red. The phenomenon is related to both the physical chemistry properties of the substance and the physiological response of the human visual system to colour. This combined physicochemical–physiological basis was first explained in 2007. In gemstones, dichromatism is sometimes referred to as the 'Usambara effect'. Physical explanation Dichromatic properties can be explained by the Beer–Lambert law an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orange G
Orange G also called C.I. 16230, Acid Orange 10, or orange gelb is a synthetic azo dye used in histology in many staining formulations. It usually comes as a disodium salt. It has the appearance of orange crystals or powder. Staining Orange G is used in the Papanicolaou stain to stain keratin. It is also a major component of the Alexander test for pollen staining. It is often combined with other yellow dyes and used to stain erythrocytes in the trichrome methods. Color marker Orange G can be used as an electrophoretic color marker to monitor the process of agarose gel electrophoresis, running approximately at the size of a 50 Base pair (bp) DNA molecule, and polyacrylamide gel electrophoresis. Bromophenol blue and xylene cyanol Xylene cyanol can be used as an electrophoretic color marker, or tracking dye, to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Bromophenol blue and orange G Orange G also called C.I. 16230, Acid . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylene Cyanol
Xylene cyanol can be used as an electrophoretic color marker, or tracking dye, to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Bromophenol blue and orange G Orange G also called C.I. 16230, Acid Orange 10, or orange gelb is a synthetic azo dye used in histology in many staining formulations. It usually comes as a disodium salt. It has the appearance of orange crystals or powder. Staining Orange G ... can also be used for this purpose. Once mixed with the sample, the concentration of xylene cyanol is typically about 0.005% to 0.03%. Migration speed In 1% agarose gels, xylene cyanol migrates at about the same rate as a 4 to 5 kilobase pair DNA fragment,{{cite book , author = Lela Buckingham and Maribeth L. Flaws , title = Molecular Diagnostics: Fundamentals, Methods, & Clinical Applications , url = https://archive.org/details/moleculardiagnos00lela , url-access = limited , publisher = F.A. Davis Company , date = 2007 , pag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TBE Buffer
TBE or Tris/Borate/EDTA, is a buffer solution containing a mixture of Tris base, boric acid and EDTA. In molecular biology, TBE and TAE buffers are often used in procedures involving nucleic acids, the most common being electrophoresis. Tris-acid solutions are effective buffers for slightly basic conditions, which keep DNA deprotonated and soluble in water. EDTA is a chelator of divalent cations, particularly of magnesium (Mg2+). As these ions are necessary co-factors for many enzymes, including contaminant nucleases, the role of the EDTA is to protect the nucleic acids against enzymatic degradation. But since Mg2+ is also a co-factor for many useful DNA-modifying enzymes such as restriction enzymes and DNA polymerases, its concentration in TBE or TAE buffers is generally kept low (typically at around 1 mM). More recently discovered substitutes for TBE and TAE buffers for electrophoresis are available. Recipe (1 liter of 5X stock solution) *54 g of Tris base (CAS# 77-86-1, free b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophoretic Color Marker
An electrophoretic color marker is used to monitor the progress of agarose gel electrophoresis and polyacrylamide gel electrophoresis (PAGE) since DNA, RNA, and most proteins are colourless. They are also referred to as tracking dyes, and are frequently present in loading dyes as well as molecular weight ladders. Examples Commonly used color markers include Bromophenol blue, Cresol Red, Orange G and Xylene cyanol. Generally speaking, Orange G migrates faster than bromophenol blue, which migrates faster than xylene cyanol, but the apparent "sizes" of these dyes (compared to DNA molecules) varies with the concentration of agarose and the buffer system used. For instance, in a 1% agarose gel made in TAE buffer (Tris-acetate-EDTA), xylene cyanol migrates at the speed of a 3000 base pair (bp) molecule of DNA and bromophenol blue migrates at 400 bp. However, in a 1% gel made in TBE buffer (Tris-borate A borate is any of several boron oxyanions, negative ions consisting of boron and oxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
