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30-880: KLH may refer to: Keyhole limpet hemocyanin , a carrier protein Kolhapur Airport (IATA code KLH), a regional airport in Kolhapur, Maharashtra, India Korean Light Helicopter, a designation used by the Republic of Korea Army KLH (company) , an audio company founded in 1957 in Cambridge, Massachusetts, United States KLH-Arena , a set of ski jump hills in Murau, Austria KLH Vajgar Jindřichův Hradec , an ice hockey team in Jindřichův Hradec, Czech Republic WKLH (also known simply as KLH),

60-446: A solid solution is also a way to strengthen alloys . Precipitation of ceramic phases in metallic alloys such as zirconium hydrides in zircaloy cladding of nuclear fuel pins can also render metallic alloys brittle and lead to their mechanical failure. Correctly mastering the precise temperature and pressure conditions when cooling down spent nuclear fuels is therefore essential to avoid damaging their cladding and to preserve

90-429: A challenging molecule to work with because of its propensity to aggregate and precipitate. Aggregates remain immunogenic, but limit the ability to conjugate haptens, and are difficult to manipulate in the laboratory. A high-quality KLH preparation with clear opalescent blue color is the best indicator of KLH solubility. Haptens can be coupled to KLH using several methods. A simple one-step coupling can be performed using

120-425: A chemical reaction. When a barium chloride solution reacts with sulphuric acid , a white precipitate of barium sulphate is formed. When a potassium iodide solution reacts with a lead(II) nitrate solution, a yellow precipitate of lead(II) iodide is formed. Precipitate formation is useful in the detection of the type of cation in a salt . To do this, an alkali first reacts with the unknown salt to produce

150-423: A less soluble compound because of its lower chemical valence: The Walden reductor made of tiny silver crystals obtained by the immersion of a copper wire into a solution of silver nitrate is used to reduce to their lower valence any metallic ion located above the silver couple (Ag + 1 e → Ag) in the redox potential scale. Without sufficient attraction forces ( e.g. , Van der Waals force ) to aggregate

180-414: A low molecular weight such as peptides , small proteins and drug molecules that are generally not immunogenic and require the aid of a carrier protein to stimulate a response from the immune system in the form of antibody production. KLH is the most widely employed carrier protein for this purpose. KLH is an effective carrier protein for several reasons. Its large size and numerous epitopes generate

210-434: A precipitate that is the hydroxide of the unknown salt. To identify the cation, the color of the precipitate and its solubility in excess are noted. Similar processes are often used in sequence – for example, a barium nitrate solution will react with sulfate ions to form a solid barium sulfate precipitate, indicating that it is likely that sulfate ions are present. A common example of precipitation from aqueous solution

240-576: A radio station in Milwaukee, Wisconsin, United States See also [ edit ] KHL Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title KLH . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=KLH&oldid=1070352071 " Category : Disambiguation pages Hidden categories: Short description

270-446: A substantial immune response, and abundance of lysine residues for coupling haptens allows a high hapten:carrier protein ratio, increasing the likelihood of generating hapten-specific antibodies. In addition, because KLH is derived from the limpet, a gastropod, it is phylogenetically distant from mammalian proteins, thus reducing false positives in immunologically-based research techniques in mammalian model organisms. KLH can also be

300-498: A superior carrier protein for cancer vaccines are creating a significant biopharmaceutical market for KLH formulations. Assays to monitor humoral immune responses against KLH in human serum have been developed to facilitate optimal use of biomedical KLH applications. Because of the beneficial uses of KLH, the Giant Keyhole Limpet , from which KLH is derived, has been a subject of growing concern among fisheries biologists in

330-402: A variety of cancer vaccines , including non-Hodgkin's lymphoma , cutaneous melanoma , breast and bladder cancer. These vaccines contain specific tumor-associated antigens conjugated to KLH to stimulate anti-tumor immune responses which can destroy tumor cells. The rapidly growing interest in therapeutic vaccines (i.e. active immunotherapies) for cancer and the documented efficacy of KLH as

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360-400: Is added to the dimethylformamide (DMF) solution in which the reaction occurred, and the product precipitates. Precipitation is useful in purifying many other products: e.g. , crude bmim -Cl is taken up in acetonitrile , and dropped into ethyl acetate , where it precipitates. Proteins purification and separation can be performed by precipitation in changing the nature of the solvent or

390-450: Is different from Wikidata All article disambiguation pages All disambiguation pages Keyhole limpet hemocyanin There are two keyhole limpet hemocyanin genes, termed KLH1 and KLH2 which share around 60% identity at the protein level. Both encode large glycosylated proteins consisting of around 3400 amino acids and a molecular weight of around 390,000 daltons , excluding

420-419: Is in ethanol precipitation of DNA . In solid phases, precipitation occurs if the concentration of one solid is above the solubility limit in the host solid, due to e.g. rapid quenching or ion implantation , and the temperature is high enough that diffusion can lead to segregation into precipitates. Precipitation in solids is routinely used to synthesize nanoclusters . In metallurgy , precipitation from

450-402: Is purified from the hemolymph of Megathura crenulata by a series of steps that typically includes ammonium sulfate precipitation and dialysis, and may involve chromatographic purification to obtain the highest purity. KLH purification may also include endotoxin removal, but this step is often unnecessary because the endotoxin serves as an adjuvant when injected for antibody production. If

480-408: Is that of silver chloride . When silver nitrate (AgNO 3 ) is added to a solution of potassium chloride (KCl) the precipitation of a white solid (AgCl) is observed. The ionic equation allows to write this reaction by detailing the dissociated ions present in aqueous solution. The Walden reductor is an illustration of a reduction reaction directly accompanied by the precipitation of

510-555: Is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate . In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant . The clear liquid remaining above the precipitated or the centrifuged solid phase is also called the supernate or supernatant . The notion of precipitation can also be extended to other domains of chemistry ( organic chemistry and biochemistry ) and even be applied to

540-537: The carbodiimide crosslinker EDC to covalently attach carboxyls to primary amines. This method is the simplest to perform and the "random" orientation allows for antibody generation against all possible epitopes, but it generally results in some degree of polymerization, which decreases solubility making the conjugate more difficult to handle. KLH can be activated with the crosslinker Sulfo-SMCC , which converts lysine residues to sulfhydryl-reactive maleimide groups. A sulfhydryl-containing hapten can then be reacted with

570-461: The KLH to complete the immunogen without causing polymerization. The specificity of this reaction is ideal for situations where the cysteine is located away from the desired epitope (e.g. in peptides where a terminal cysteine can be added to either end of the peptide). Maleimide activated KLH, where the first part of this two step procedure has been completed, is commercially available. KLH is being tested in

600-413: The bound copper is found as Cu and hemocyanin is colorless. The KLH protein is potently immunogenic, but does not cause an adverse immune response in humans. It is therefore highly prized as a vaccine carrier protein. Because of its size and glycosylation, KLH protein cannot be reproduced synthetically; it is available only as a purified biological product from the keyhole limpet Megathura crenulata . KLH

630-456: The glycosylation. The protein oligomerises to form a barrel shaped didecameric complex which is composed of 20 monomers. Each domain of a KLH subunit contains two copper atoms that together bind a single oxygen molecule (O 2 ). When oxygen is bound to hemocyanin, the molecule takes on a distinctive transparent , opalescent blue color, due to the Cu state of the copper. In the absence of oxygen,

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660-401: The photograph here beside: [REDACTED] Precipitation may also occur when an antisolvent (a solvent in which the product is insoluble) is added, drastically reducing the solubility of the desired product. Thereafter, the precipitate may be easily separated by decanting , filtration , or by centrifugation . An example would be the synthesis of Cr tetraphenylporphyrin chloride: water

690-641: The potential exists to "decimate their populations". To help assure a secure long-term source of KLH for the many Federally sponsored biomedical research programs using KLH, Federal agencies including the National Institutes of Health and the National Science Foundation have also sponsored research to establish sustainable mariculture production of the Giant Keyhole Limpet. Precipitate In an aqueous solution , precipitation

720-406: The product of the reaction is insoluble in the solvent used for the reaction. Thus, it precipitates as it is formed, preferably forming pure crystals . An example of this would be the synthesis of porphyrins in refluxing propionic acid . By cooling the reaction mixture to room temperature, crystals of the porphyrin precipitate, and are collected by filtration on a Büchner filter as illustrated by

750-484: The protein becomes denatured or if the copper ions are lost in the purification process, the opalescent blue color disappears and the solution becomes a dull grayish color. Denaturation of KLH also results in a tendency of the protein to aggregate and precipitate from solution. Keyhole limpet hemocyanin (KLH) is used extensively as a carrier protein in the production of antibodies for research, biotechnology and therapeutic applications. Haptens are substances with

780-400: The solid particles together and to remove them from solution by gravity ( settling ), they remain in suspension and form colloids . Sedimentation can be accelerated by high speed centrifugation . The compact mass thus obtained is sometimes referred to as a 'pellet'. Digestion, or precipitate ageing , happens when a freshly formed precipitate is left, usually at a higher temperature , in

810-405: The solid phases (e.g. metallurgy and alloys ) when solid impurities segregate from a solid phase. The precipitation of a compound may occur when its concentration exceeds its solubility . This can be due to temperature changes, solvent evaporation, or by mixing solvents. Precipitation occurs more rapidly from a strongly supersaturated solution. The formation of a precipitate can be caused by

840-484: The solution from which it precipitates. It results in purer and larger recrystallized particles. The physico-chemical process underlying digestion is called Ostwald ripening . While precipitation reactions can be used for making pigments , removing ions from solution in water treatment , and in classical qualitative inorganic analysis , precipitation is also commonly used to isolate the products of an organic reaction during workup and purification operations. Ideally,

870-505: The state of California due to the possibility of overharvest of the species for commercial purposes. Giant Keyhole Limpets are not an abundant species to begin with, and some divers have reported a decline in their populations. In a 2006 report from the Marine Science Institute, University of California, Santa Barbara, scientists state that they are "very concerned about the emerging fishery" for Giant Keyhole Limpets and suggest

900-430: The value of its relative permittivity ( e.g. , by replacing water by ethanol ), or by increasing the ionic strength of the solution. As proteins have complex tertiary and quaternary structures due to their specific folding and various weak intermolecular interactions ( e.g. , hydrogen bridges), these superstructures can be modified and proteins denaturated and precipitated. Another important application of an antisolvent

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