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Van Den Bergh Reaction
Van den Bergh reaction is a chemical reaction used to measure bilirubin levels in blood. More specifically, it determines the amount of conjugated bilirubin in the blood. The reaction produces azobilirubin. Principle: bilirubin reacts with diazotised sulfanilic acid, sulphanilic acid to produce purple coloured azobilirubin. This reaction is highly useful in understanding the nature of jaundice. This was pioneered by the Dutch physician, Abraham Albert Hijmans van den Bergh (1869–1943) of Utrecht. This test helps to identify the type of jaundice. The serum of the patient is mixed with diazo reagent. If a red colour develops immediately it is called a direct positive. It happens if conjugated bilirubin is present. In an indirect positive test, the patient's serum is first treated with alcohol and later mixed with diazo reagent. This causes development of a red colour. It is seen if unconjugated bilirubin is present. If both conjugated and unconjugated bilirubin are present the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilirubin
Bilirubin (BR) (adopted from German, originally bili—bile—plus ruber—red—from Latin) is a red-orange compound that occurs in the normcomponent of the straw-yellow color in urine. Another breakdown product, stercobilin, causes the brown color of feces. Although bilirubin is usually found in animals rather than plants, at least one plant species, '' Strelitzia nicolai'', is known to contain the pigment. Structure Bilirubin consists of an open-chain tetrapyrrole. It is formed by oxidative cleavage of a porphyrin in heme, which affords biliverdin. Biliverdin is reduced to bilirubin. After conjugation with glucuronic acid, bilirubin is water-soluble and can be excreted. Bilirubin is structurally similar to the pigment phycobilin used by certain algae to capture light energy, and to the pigment phytochrome used by plants to sense light. All of these contain an open chain of four pyrrolic rings. Like these other pigments, some of the double-bonds in bilirubin isomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azobilirubin
Azobilirubin is a coloured compound formed by the condensation of diazotized sulfanilic acid with bilirubin in the van den Bergh reaction. The quantity of bilirubin in patients with jaundice can be determined by the formation of azobilirubin in the presence of methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab .... The Van den Bergh chemical reaction which is used to measure bilirubin levels, couples bilirubin with diazotized sulfanilic acid. This reaction produced azo pigments, or azobilirubin. The presence of azobilirubin is best indicated by the emergence of a pink-purple color. The intensity of the color will also indicate how much bilirubin is in the blood. Color markers and indicators can be changed. Adding alkaline tartrate can make the purple azobilirubin into a blue a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfanilic Acid
Sulfanilic acid (4-aminobenzenesulfonic acid) is an organic compound with the formula H3NC6H4SO3. It is an off-white solid. It is a zwitterion, which explains its high melting point. It is a common building block in organic chemistry."Sulphanilic acid". ''A Dictionary of Chemistry''. Oxford University Press, 2000. Oxford Reference Online. Oxford University Press. Synthesis Sulfanilic acid can be produced by sulfonation of aniline with concentrated sulfuric acid.Siegfried Hauptmann: ''Organische Chemie'', 2nd Edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 511, . This proceeds via phenylsulfamic acid; a zwitterion with a N-S bond. Eugen Bamberger originally proposed a mechanism involving a series of intramolecular rearrangements, with phenylsulfamic acid forming orthanilic acid, which rearranged to sulfanilic acid on heating. Subsequent radiosulphur studies showed that the process is intermolecular, with the phenylsulfamic acid desulfating to generate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jaundice
Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life. The most commonly associated symptoms of jaundice are itchiness, pale feces, and dark urine. Normal levels of bilirubin in blood are below 1.0 mg/ dl (17 μmol/ L), while levels over 2–3 mg/dl (34–51 μmol/L) typically result in jaundice. High blood bilirubin is divided into two types: unconjugated and conjugated bilirubin. Causes of jaundice vary from relatively benign to potentially fatal. High unconjugated bilirubin may be due to excess red blood cell breakdown, large bruises, gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abraham Albert Hijmans Van Den Bergh
Abraham Albert Hijmans van den Bergh (1 December 1869, in Rotterdam – 28 September 1943, in Utrecht) was a Dutch physician specializing in internal medicine. Hijmans van den Bergh is best known for his Van den Bergh reaction Van den Bergh reaction is a chemical reaction used to measure bilirubin levels in blood. More specifically, it determines the amount of conjugated bilirubin in the blood. The reaction produces azobilirubin. Principle: bilirubin reacts with diazotis .... In 1919 he became member of the Royal Netherlands Academy of Arts and Sciences. Hijmans van den Bergh was of Jewish descent, but neither he or his parents were religiously observant, nor members of a Jewish worship community. Later in life he joined the Remonstrant Church. His final years were spent under the German occupation of the Netherlands; he was spared persecution due to being in a "mixed marriage". References External links Biography at inghist.nlHijmans van den Bergh Building {{DEFAULTSOR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utrecht
Utrecht ( ; ; ) is the List of cities in the Netherlands by province, fourth-largest city of the Netherlands, as well as the capital and the most populous city of the Provinces of the Netherlands, province of Utrecht (province), Utrecht. The municipality of Utrecht is located in the eastern part of the Randstad conurbation, in the very centre of mainland Netherlands, and includes Haarzuilens, Vleuten and De Meern. It has a population of 376,435 as of . Utrecht's ancient city centre features many buildings and structures, several dating as far back as the High Middle Ages. It has been the religious centre of the Netherlands since the 8th century. In 1579, the Union of Utrecht was signed in the city to lay the foundations for the Dutch Republic. Utrecht was the most important city in the Netherlands until the Dutch Golden Age, when it was surpassed by Amsterdam as the country's cultural centre and most populous city. Utrecht is home to Utrecht University, the largest university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Tests
A chemical substance is a unique form of matter with constant chemical composition and characteristic properties. Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. Chemical substances can exist in several different physical states or phases (e.g. solids, liquids, gases, or plasma) without changing their chemical composition. Substances transition between these phases of matter in response to changes in temperature or pressure. Some chemical substances can be combined or converted into new substances by means of chemical reactions. Chemicals that do not possess this ability are said to be inert. Pure water is an example of a chemical substance, with a constant composition of two hydrogen atoms bonded to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
