https://en.bharatpedia.org/w/index.php?action=history&feed=atom&title=ReagentReagent - Revision history2026-08-07T10:31:55ZRevision history for this page on the wikiMediaWiki 1.43.6https://en.bharatpedia.org/w/index.php?title=Reagent&diff=297531&oldid=prev>4 view 4 at 23:25, 13 April 20212021-04-13T23:25:32Z<p></p>
<p><b>New page</b></p><div>{{short description|Substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs}}<br />
{{distinguish|Regent}}<br />
{{redirect-distinguish|Reactants|Reactance (disambiguation){{!}}Reactance}}<br />
[[Image:SulfurReagent.jpg|right|200px|thumb|Reactants, such as [[sulfur]] (''pictured''), are the starting materials that are used in chemical reactions.]]<br />
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A '''reagent''' {{IPAc-en|r|i|ˈ|eɪ|dʒ|ən|t|}} is a substance or compound added to a system to cause a [[chemical reaction]], or added to test if a reaction occurs.<ref name=gold>{{GoldBookRef|title=Reactant |file=R05163 |year=1996}}</ref> The terms ''reactant'' and ''reagent'' are often used interchangeably—however, a '''reactant''' is more specifically a substance ''consumed'' in the course of a chemical reaction.<ref name=gold/> ''[[Solvent]]s'', though involved in the [[reaction mechanism]], are usually not called reactants. Similarly, ''[[catalysis|catalysts]]'' are not consumed by the reaction, so they are not reactants. In [[biochemistry]], especially in connection with [[enzyme]]-catalyzed reactions, the reactants are commonly called [[substrate (biochemistry)|substrates]].<br />
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==Organic chemistry==<br />
In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the [[Collins reagent]], [[Fenton's reagent]], and [[Grignard reagent]]s. In analytical chemistry, a reagent is a compound or mixture used to detect the presence or absence of another substance, e.g. by a color change, or to measure the concentration of a substance, e.g. by [[Colorimetry (chemical method)|colorimetry]]. Examples include [[Fehling's reagent]], [[Millon's reagent]], and [[Tollens' reagent]].<br />
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==Commercial or laboratory preparations==<br />
In commercial or laboratory preparations, {{anchor|Reagent_grade}}'''[[chemical purity|reagent-grade]]''' designates [[chemical substance]]s meeting [[standardization|standards]] of [[purity (gas)|purity]] that ensure the scientific precision and reliability of [[chemical analysis]], chemical reactions or physical testing. Purity standards for reagents are set by organizations such as [[ASTM International]] or the [[American Chemical Society]]. For instance, reagent-quality water must have very low levels of impurities such as [[sodium]] and [[chloride]] ions, [[silica]], and bacteria, as well as a very high [[electrical resistivity]]. Laboratory products which are '''less''' pure, but still useful and economical for undemanding work, may be designated as ''technical'', ''practical'', or ''crude'' grade to distinguish them from reagent versions.<br />
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==Biology==<br />
In the field of biology, the [[biotechnology]] revolution in the 1980s grew from the development of reagents that could be used to identify and manipulate the chemical matter in and on cells.<ref>{{cite news|last1=Fox|first1=Jeffrey L.|title=Antibody reagents revolutionizing immunology|work=Chemical & Engineering News Archive|date=1 January 1979|pages=15–17|doi=10.1021/cen-v057n001.p015}}</ref><ref name=NIHreport1998>{{cite web |title=Report of the National Institutes of Health (NIH) Working Group on Research Tools|url=http://www.nih.gov/news/researchtools/index.htm|publisher=NIH|archive-url=https://web.archive.org/web/20000816014021/http://www.nih.gov/news/researchtools/index.htm |archive-date=August 16, 2000|date=June 4, 1998}}</ref> These reagents included [[Antibody#Research applications|antibodies]] ([[Polyclonal antibodies|polyclonal]] and [[Monoclonal antibody|monoclonal]]), [[oligomers]], all sorts of [[model organisms]] and [[immortalised cell line]]s, reagents and methods for [[molecular cloning]] and [[DNA replication]], and many others.<ref name=NIHreport1998/><ref>{{cite journal |last1=Ishino |first1=S|last2=Ishino|first2=Y|title=DNA polymerases as useful reagents for biotechnology: the history of developmental research in the field |journal=Frontiers in Microbiology|date=29 August 2014|volume=5|pages=465|pmid=25221550|pmc=4148896|doi=10.3389/fmicb.2014.00465}}</ref><br />
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Tool compounds are also important reagents in biology; they are small molecules or biochemicals like [[siRNA]] or antibodies that are known to affect a given biomolecule—for example a [[drug target]]—but are unlikely to be useful as drugs themselves, and are often starting points in the [[drug discovery]] process.<ref>{{cite journal |last1=Kenakin|first1=T|last2=Bylund|first2=DB|last3=Toews|first3=ML|last4=Mullane|first4=K|last5=Winquist|first5=RJ|last6=Williams|first6=M|title=Replicated, replicable and relevant-target engagement and pharmacological experimentation in the 21st century |journal=Biochemical Pharmacology|date=1 January 2014 |volume=87 |issue=1 |pages=64–77 |doi=10.1016/j.bcp.2013.10.024|pmid=24269285}}</ref><ref>{{cite journal|last1=Lindsley|first1=CW|title=2013 Philip S. Portoghese Medicinal Chemistry Lectureship: drug discovery targeting allosteric sites|journal=Journal of Medicinal Chemistry|date=25 September 2014 |volume=57 |issue=18 |pages=7485–7498|pmid=25180768|pmc=4174999|doi=10.1021/jm5011786}}</ref> Many natural products, such as [[curcumin]], are hits in almost any assay in which they are tested, are not useful tool compounds, and are classified by medicinal chemists as "[[pan-assay interference compounds]]".<ref>{{cite journal|last1=Baker|first1=Monya|title=Deceptive curcumin offers cautionary tale for chemists |journal=Nature |date=9 January 2017|volume=541|issue=7636|pages=144–145|doi=10.1038/541144a|pmid=28079090|bibcode=2017Natur.541..144B|doi-access=free}}</ref><ref>{{cite journal|last1=Dahlin|first1=JL|last2=Walters|first2=MA|title=The essential roles of chemistry in high-throughput screening triage |journal=[[Future Medicinal Chemistry]]|date=July 2014|volume=6|issue=11|pages=1265–1290|pmid=25163000|pmc=4465542|doi=10.4155/fmc.14.60}}</ref><ref>{{cite journal|last1=Baell|first1=JB|last2=Holloway|first2=GA|title=New substructure filters for removal of pan assay interference compounds (PAINS) from screening libraries and for their exclusion in bioassays.|journal=Journal of Medicinal Chemistry |date=8 April 2010|volume=53|issue=7|pages=2719–2740|doi=10.1021/jm901137j|pmid=20131845|citeseerx=10.1.1.394.9155}}</ref><br />
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==See also==<br />
* [[Limiting reagent]]<br />
* [[List of reagents|Common reagents]]<br />
* [[Product (chemistry)|Product]]<br />
* [[Substrate (chemistry)|Substrate]]<br />
* {{in title}}<br />
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==References==<br />
{{reflist}}<br />
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==External links==<br />
{{Commonscat|Reagents}}<br />
{{Wiktionary|reagent|reactant}}<br />
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{{Authority control}}<br />
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[[Category:Reagents| ]]<br />
[[Category:Reagents for organic chemistry| ]]<br />
[[Category:Biological techniques and tools]]<br />
[[Category:Chemical reactions]]<br />
[[Category:Reagents for biochemistry]]</div>>4 view 4