View source for Dimethyl sulfoxide

{{short description|Organosulfur chemical compound used as a solvent}}
{{Redirect|DMSO}}
{{Chembox
| Watchedfields  = changed
| verifiedrevid  = 476997700
| ImageFile1     = DMSO-2D-dimensions.svg
| ImageFileL2    = Dimethyl-sulfoxide-3D-balls-A.png
| ImageFileL2_Ref = {{chemboximage|correct|??}}
| ImageNameL2    = Stereo structural formula of dimethyl sulfoxide with an explicit electron pair and assorted dimensions
| ImageFileR2    = DMSO-3D-vdW.png
| ImageFileR2_Ref = {{Chemboximage|correct|??}}
| ImageNameR2    = Spacefill model of dimethyl sulfoxide
| ImageFile3     = Sample of Dimethyl sulfoxide 01.jpg
| ImageCaption3  = A sample of dimethyl sulfoxide
| PIN            = (Methanesulfinyl)methane
| SystematicName = (Methanesulfinyl)methane <small>(substitutive)</small><br />
Dimethyl(oxido)sulfur <small>(additive)</small>
| OtherNames     = Methylsulfinylmethane<br />
Methyl sulfoxide (2:1), Dermasorb<ref>DMSO (medication)</ref>
| Section1       = {{Chembox Identifiers
| Abbreviations = DMSO, Me2SO
| CASNo = 67-68-5
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 679
| ChemSpiderID = 659
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| UNII = YOW8V9698H
| UNII_Ref = {{fdacite|correct|FDA}}
| EINECS = 200-664-3
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB01093
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D01043
| MeSHName = Dimethyl+sulfoxide
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 28262
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 504
| RTECS = PV6210000
| Gmelin = 1556
| Beilstein = 506008
| SMILES = CS(=O)C
| SMILES1 = CS(C)=O
| StdInChI = 1S/C2H6OS/c1-4(2)3/h1-2H3
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| InChI = 1/C2H6OS/c1-4(2)3/h1-2H3
| StdInChIKey = IAZDPXIOMUYVGZ-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| InChIKey = IAZDPXIOMUYVGZ-UHFFFAOYAR}}
| Section2       = {{Chembox Properties
| C=2 | H=6 | O=1 | S=1
| Appearance = Colourless liquid
| Density = 1.1004{{nbsp}}g⋅cm<sup>−3</sup>
| VaporPressure = {{convert|0.556|mbar|kPa|abbr = out| disp = or}} at 20&nbsp;°C<ref name="Atofina">{{Cite web|url=http://www.bulkmsm.com/research/msm/page12.htm|title=Dimethyl Sulfoxide (DMSO) -- Technical|access-date=26 May 2007|publisher=Atofina Chemicals, inc}}</ref>
| Solubility = Miscible
| Solvent = [[Diethyl ether]]
| SolubleOther = Not soluble
| MeltingPtC = 19
| BoilingPtC = 189
| Viscosity = 1.996{{nbsp}}[[Poise (unit)|cP]] at 20&nbsp;°C
| RefractIndex = 1.479<br /> [[Dielectric constant|ε<sub>r</sub>]] = 48
| pKa = 35<ref>{{cite journal | vauthors = Matthews WS, Bares JE, Bartmess JE, Bordwell FG, Cornforth FJ, Drucker GE, Margolin Z, McCallum RJ, McCollum GJ, Vanier NR | journal = J. Am. Chem. Soc. | year = 1975 | volume = 97 | pages = 7006–7014 | doi = 10.1021/ja00857a010 | title = Equilibrium acidities of carbon acids. VI. Establishment of an absolute scale of acidities in dimethyl sulfoxide solution | issue = 24 }}</ref> 
  }}
| Section3       = {{Chembox Structure
| Dipole = 3.96{{nbsp}}[[Debye|D]]
| PointGroup = C<sub>s</sub>
| MolShape = Trigonal pyramidal
  }}
| Section6       = {{Chembox Pharmacology
| ATCCode_prefix = G04
| ATCCode_suffix = BX13
| ATC_Supplemental = {{ATC|M02|AX03}}
}}
| Section7       = {{Chembox Hazards
| MainHazards = Irritant
| ExternalSDS = [http://ptcl.chem.ox.ac.uk/MSDS/ME/methyl_sulfoxide.html Oxford MSDS]
| NFPA-H = 1
| NFPA-F = 2
| NFPA-R = 0
| GHS_ref=<ref>{{cite web |title=Dimethyl sulfoxide |url=https://pubchem.ncbi.nlm.nih.gov/compound/679#section=Safety-and-Hazards |website=pubchem.ncbi.nlm.nih.gov |language=en}}</ref>
| FlashPtC = 89
  }}
| Section8       = {{Chembox Related
| OtherFunction_label = [[sulfoxide]]s
| OtherFunction = [[Diethyl sulfoxide]]
| OtherCompounds = {{ubl
 | [[Sodium methylsulfinylmethylide]],
 | [[Dimethyl sulfide]],
 | [[Methylsulfonylmethane|Dimethyl sulfone]],
 | [[Acetone]]
 }}
  }}
}}
'''Dimethyl sulfoxide''' ('''DMSO''') is an [[organosulfur compound]] with the [[chemical formula|formula]] ([[methyl|CH<sub>3</sub>]])<sub>2</sub>{{chem|[[sulfur|S]]|[[oxygen|O]]}}.  This colorless liquid is the [[sulfoxide]] most widely used commercially. It is an important [[polar solvent|polar]] [[aprotic solvent]] that dissolves both [[chemical polarity|polar and nonpolar]] compounds and is [[miscible]] in a wide range of organic solvents as well as water.  It has a relatively high boiling point.  DMSO is metabolised to compounds that leave a [[garlic]]-like taste in the mouth after DMSO is absorbed by skin.<ref>{{Cite book | veditors = Novak KM | title = Drug Facts and Comparisons | edition = 56th | publisher = Wolters Kluwer Health. | location = St. Louis, Missouri | year = 2002 | page = [https://archive.org/details/drugfactscompari00kast/page/2345 2345] | isbn = 978-1-57439-110-7 | url-access = registration | url = https://archive.org/details/drugfactscompari00kast/page/619 }}</ref>

In terms of chemical structure, the molecule has idealized [[Molecular symmetry#Common point groups|C<sub>s</sub>]] [[symmetry group|symmetry]]. It has a [[trigonal pyramidal molecular geometry]] consistent with other three-coordinate S(IV) compounds,<ref>{{cite journal | vauthors = Thomas R, Shoemaker CB, Eriks K | year = 1966 | title = The Molecular and Crystal Structure of Dimethyl Sulfoxide, (H<sub>3</sub>C)<sub>2</sub>SO | journal = Acta Crystallogr | volume = 21 | issue = 1 | pages = 12–20 | doi = 10.1107/S0365110X66002263 | bibcode = 1966AcCry..21...12T }}</ref> with a [[lone pair|nonbonded electron pair]] on the approximately [[Tetrahedral molecular geometry|tetrahedral]] sulfur atom.

==Synthesis and production==
Dimethyl sulfoxide was first synthesized in 1866 by the Russian scientist [[Alexander Mikhaylovich Zaytsev|Alexander Zaytsev]], who reported his findings in 1867.<ref name="Erlenmeyer">{{cite book |editor-last=Erlenmeyer |editor-first=E. |editor-last2=Rieckher | editor-first2=T. |editor-last3=Volhard |editor-first3=J. |editor-last4=Liebig |editor-first4=J. | editor-last5=Wöhler |editor-first5=F. |author=von Demselben | title=Annalen der Pharmacie | publisher=Meyer ; Winter | issue=v. 144 | year=1867 | url=https://books.google.com/books?id=uelSAAAAcAAJ&pg=PA148 |chapter=Ueber die Einwirkung von Saltpetersäure auf Schwefelmethyl und Schwefeläthyl |trans-chapter=On the effect of nitric acid on methyl sulfide and ethyl sulfide | language=de | page=148}}</ref>  Its modern use as an industrial solvent began through popularization by Thor Smedslund at the Stepan Chemical Company.<ref>{{cite book|url=|title=Excuse me sir, would you like to buy a kilo of isopropyl bromide?|first=Max&nbsp;G.|last=Gergel|author-link=Max Gergel|date=March 1977|publisher=Pierce Chemical|page=145}}</ref>  Dimethyl sulfoxide is produced industrially from [[dimethyl sulfide]], a by-product of the [[Kraft process]], by oxidation with oxygen or [[nitrogen dioxide]].<ref name="Roy">{{citation | last=Roy | first=Kathrin-Maria | title=Ullmann's Encyclopedia of Industrial Chemistry | chapter=Sulfones and Sulfoxides | publisher=Wiley-VCH Verlag GmbH & Co. KGaA | publication-place=Weinheim, Germany | date=15 June 2000 | doi=10.1002/14356007.a25_487| isbn=3527306730 }}</ref>

==Reactions==

===Reactions with electrophiles===
The sulfur center in DMSO is [[nucleophilic]] toward soft [[electrophile]]s and the oxygen is nucleophilic toward hard electrophiles.  With [[methyl iodide]] it forms [[trimethylsulfoxonium iodide]], [(CH<sub>3</sub>)<sub>3</sub>SO]I:

:(CH<sub>3</sub>)<sub>2</sub>SO  +  CH<sub>3</sub>I  →  [(CH<sub>3</sub>)<sub>3</sub>SO]I

This salt can be [[deprotonated]] with [[sodium hydride]] to form the [[sulfur]] [[ylide]]:

:[(CH<sub>3</sub>)<sub>3</sub>SO]I  +  NaH  → (CH<sub>3</sub>)<sub>2</sub>S(CH<sub>2</sub>)O  +  NaI  +  H<sub>2</sub>

===Acidity===
The methyl groups of DMSO are only weakly acidic, with a {{nowrap|p''K''<sub>a</sub> {{=}} 35}}.  For this reason, the basicities of many weakly basic organic compounds have been examined in this solvent.

Deprotonation of DMSO requires strong bases like [[lithium diisopropylamide]] and [[sodium hydride]].  Stabilization of the resultant [[carbanion]] is provided by the S(O)R group.  The sodium derivative of DMSO formed in this way is referred to as ''[[dimsyl sodium]]''.  It is a base, e.g., for the deprotonation of [[ketones]] to form sodium [[enolates]], [[phosphonium salt]]s to form [[Wittig reagent]]s, and [[formamidinium]] salts to form [[diaminocarbene]]s.  It is also a potent nucleophile.

===Oxidant===
In [[organic synthesis]], DMSO is used as a mild oxidant.<ref>{{cite journal |vauthors=Epstein WW, Sweat FW |date=March 1967 |title=Dimethyl Sulfoxide Oxidations |journal=[[Chemical Reviews]] |volume=67 |issue=3 |pages=247–260 |pmid=6042131 |doi=10.1021/cr60247a001}}</ref> It forms the basis of several selective [[sulfonium-based oxidation of alcohols to aldehydes|sulfonium-based oxidation reactions]] including the [[Pfitzner–Moffatt oxidation]], [[Corey–Kim oxidation]] and the [[Swern oxidation]].<ref>{{cite journal |vauthors=Tidwell TT |year=1990 |title=Oxidation of Alcohols by Activated Dimethyl Sulfoxide and Related Reactions: An Update |journal=[[Synthesis (journal)|Synthesis]] |volume=1990 |issue=10 |pages=857–870 |doi=10.1055/s-1990-27036}}</ref> The [[Kornblum oxidation]] is conceptually similar. These all involve formation of an intermediate [[sulfonium]] species (R<sub>2</sub>S<sup>+</sup>X where X is a heteroatom)

===Ligand and Lewis base===
Related to its ability to dissolve many salts, DMSO is a common [[ligand]] in [[coordination chemistry]].<ref>{{cite journal | doi = 10.1016/j.ccr.2004.02.005| title = Structure and bonding in metal sulfoxide complexes: An update| journal = Coordination Chemistry Reviews| volume = 248| issue = 3–4| pages = 351–375| year = 2004| vauthors = Calligaris M }}</ref> Illustrative is the complex [[dichlorotetrakis(dimethyl sulfoxide)ruthenium(II)]] (RuCl<sub>2</sub>(dmso)<sub>4</sub>). In this complex, three DMSO ligands are bonded to [[ruthenium]] through sulfur. The fourth DMSO is bonded through oxygen. In general, the oxygen-bonded mode is more common.

In carbon tetrachloride solutions DMSO functions as a Lewis base with a variety of Lewis acids such as [[iodine|I<sub>2</sub>]], [[phenol]]s, [[trimethyltin chloride]], metalloporphyrins, and the dimer [[Rhodium carbonyl chloride|Rh<sub>2</sub>Cl<sub>2</sub>(CO)<sub>4</sub>]]. The donor properties are discussed in the [[ECW model]]. The relative donor strength of DMSO toward a series of acids, versus other Lewis bases, can be illustrated by [[ECW model|C-B plots]].<ref name="Laurence Gal">{{cite book | last1=Laurence | first1=Christian | last2=Gal | first2=Jean-François | title=Lewis basicity and affinity scales : data and measurement | publisher=John Wiley | publication-place=Chichester, West Sussex, U.K. | date=2010 | isbn=978-0-470-74957-9 | oclc=428031803 | pages=50–51}}</ref><ref>{{cite journal|author1=Cramer, R. E. |author2=Bopp, T. T. |year=1977|title= Graphical display of the enthalpies of adduct formation for Lewis acids and bases |journal= Journal of Chemical Education |volume=54|pages=612–613|doi= 10.1021/ed054p612}} The plots shown in this paper used older parameters. Improved E&C parameters are listed in [[ECW model]].</ref>

==Applications==

===Solvent===
[[File:Vacuum distillation of DMSO at 70C.jpg|left|thumb|upright|Distillation of DMSO requires a partial vacuum to achieve a lower boiling point.]]
DMSO is a [[polar aprotic solvent]] and is less toxic than other members of this class, such as [[dimethylformamide]], [[dimethylacetamide]], [[Methylpyrrolidone|''N''-methyl-2-pyrrolidone]], and [[hexamethylphosphoramide]] (HMPA). DMSO is frequently used as a [[solvent]] for chemical reactions involving salts, most notably [[Finkelstein reaction]]s and other [[nucleophilic substitution]]s. It is also extensively used as an extractant in biochemistry and cell biology.<ref>{{cite web|url=http://www.exactantigen.com/review/DMSO.html|title=DMSO|access-date=2009-10-02|work=exactantigen.com|archive-url=https://web.archive.org/web/20091005075648/http://www.exactantigen.com/review/DMSO.html|archive-date=2009-10-05|url-status=dead}}</ref> Because DMSO is only weakly acidic, it tolerates relatively strong bases and as such has been extensively used in the study of [[carbanion]]s.  A set of non-aqueous [[pKa]] values (C-H, O-H, S-H and N-H acidities) for thousands of organic compounds have been determined in DMSO solution.<ref>
{{cite journal
| vauthors = Bordwell FG
| year = 1988
| title = Equilibrium acidities in dimethyl sulfoxide solution
| journal = [[Accounts of Chemical Research]]
| volume = 21
| issue = 12
| pages = 456–463
| doi = 10.1021/ar00156a004
| s2cid = 26624076
}}</ref><ref>
{{cite web |url=http://www.chem.wisc.edu/areas/reich/pkatable/ |title=Bordwell pKa Table (Acidity in DMSO) |url-status=live |archive-url=https://web.archive.org/web/20081009060809/http://www.chem.wisc.edu/areas/reich/pkatable/ |archive-date=9 October 2008 |access-date=23 April 2019}}</ref>

Because of its high boiling point, {{convert|189|C|F}}, DMSO evaporates slowly at normal atmospheric pressure. Samples dissolved in DMSO cannot as easily be recovered compared to other solvents, as it is very difficult to remove all traces of DMSO by conventional [[rotary evaporation]]. One technique to fully recover samples is removal of the organic solvent by evaporation followed by addition of water (to dissolve DMSO) and [[freeze-drying|cryodesiccation]] to remove both DMSO and water. Reactions conducted in DMSO are often diluted with water to precipitate or phase-separate products. The relatively high freezing point of DMSO, {{convert|18.5|C|F}}, means that at, or just below, room temperature it is a solid, which can limit its utility in some chemical processes (e.g. [[crystallization]] with cooling).

In its [[deuterium|deuterated]] form ([[Deuterated DMSO|DMSO-''d''<sub>6</sub>]]), it is a useful solvent for [[Nuclear magnetic resonance|NMR]] spectroscopy, again due to its ability to dissolve a wide range of analytes, the simplicity of its own spectrum, and its suitability for high-temperature NMR spectroscopic studies. Disadvantages to the use of DMSO-''d''<sub>6</sub> are its high viscosity, which broadens signals, and its [[hygroscopicity]], which leads to an overwhelming H<sub>2</sub>O resonance in the <sup>1</sup>H-NMR spectrum. It is often mixed with [[deuterated chloroform|CDCl<sub>3</sub>]] or [[deuterated dichloromethane|CD<sub>2</sub>Cl<sub>2</sub>]] for lower viscosity and melting points.

{{multiple image|align = left|perrow = 1|total_width=175|image1=MIC_microbroth_dilution.jpg| image2 = Lightmatter_lab_mice.jpg|footer = DMSO is used as a solvent in ''in vitro'' and ''in vivo'' drug testing.}}
DMSO is used to dissolve test compounds in ''[[in vitro]]'' [[drug discovery]]<ref name="pmid32529587">{{cite journal |vauthors=Cushnie TP, Cushnie B, Echeverría J, Fowsantear W, Thammawat S, Dodgson JL, Law S, Clow SM |date=June 2020 |title=Bioprospecting for antibacterial drugs: a multidisciplinary perspective on natural product source material, bioassay selection and avoidable pitfalls|journal=Pharmaceutical Research |volume=37 |issue=7 |pages=Article 125 |doi=10.1007/s11095-020-02849-1|pmid=32529587|s2cid=219590658 |url= https://zenodo.org/record/3909383}}</ref><ref name="pmid17099243">{{cite journal |vauthors=Ilouga PE, Winkler D, Kirchhoff C, Schierholz B, Wölcke J|date=November 2007 |title=Investigation of 3 industry-wide applied storage conditions for compound libraries|journal=Journal of Biomolecular Screening|volume=12 |issue=1 |pages=21–32 |doi=10.1177/1087057106295507|pmid=17099243 |doi-access=free }}</ref> and [[drug design]]<ref name="pmid16472214">{{cite journal| vauthors = Balakin KV, Savchuk NP, Tetko IV| year = 2006| title = In silico approaches to prediction of aqueous and DMSO solubility of drug-like compounds: trends, problems and solutions| journal = Current Medicinal Chemistry| volume = 13| issue = 2| pages = 223–241| pmid = 16472214| doi = 10.2174/092986706775197917}}</ref> [[bioassay|screening]] programs, including [[high-throughput screening]] programs.<ref name="pmid17099243"/><ref name="pmid16472214"/>  This is because it is able to dissolve both [[Chemical polarity#Polar molecules|polar]] and [[Chemical polarity#Nonpolar molecules|nonpolar]] compounds,<ref name="pmid32529587"/><ref name="pmid16472214"/> can be used to maintain [[stock solution]]s of test compounds (important when working with a large [[chemical library]]),<ref name="pmid17099243"/> is readily [[Miscibility|miscible]] with water and [[Growth medium|cell culture media]], and has a high boiling point (this improves the accuracy of test compound concentrations by reducing room temperature evaporation).<ref name="pmid32529587"/>  One limitation with DMSO is that it can affect [[Immortalised cell line|cell line]] growth and viability, with low DMSO concentrations sometimes stimulating cell growth, and high DMSO concentrations sometimes inhibiting or killing cells.<ref name="pmid32529587"/>

DMSO is used as a vehicle in ''[[in vivo]]'' studies of test compounds.  It has, for example, been employed as a co-solvent to assist absorption of the [[Flavonol#Flavonols glycosides|flavonol glycoside]] [[Icariin]] in the [[nematode]] worm ''[[Caenorhabditis elegans]]''.<ref name="pmid22216122">{{cite journal |vauthors=Cai WJ, Huang JH, Zhang SQ, Wu B, Kapahi P, Zhang XM, Shen ZY| title=Icariin and its derivative icariside II extend healthspan via insulin/IGF-1 pathway in C. elegans | journal=PLOS ONE | volume=6 | issue=12 | year=2011 | page=e28835 | pmid=22216122 | pmc = 3244416 | doi-access=free | doi=10.1371/journal.pone.0028835 | veditors=Blagosklonny MV | bibcode=2011PLoSO...628835C }}</ref>  As with its use in ''in vitro'' studies, DMSO has some limitations in [[Model organism|animal models]].<ref name=" kelava"/><ref name="PMID20962895"/> [[Pleiotropy (drugs)|Pleiotropic]] effects can occur and, if DMSO control groups are not carefully planned, then solvent effects can falsely be attributed to the prospective drug.<ref name="kelava">{{cite journal |vauthors=Kelava T, Cavar I | title = Biological actions of drug solvents | journal = Periodicum Biologorum | volume = 113 | issue = 3| pages = 311–320 |date=Nov 2011 | url = http://hrcak.srce.hr/74090}}</ref> For example, even a very low dose of DMSO has a powerful protective effect against [[paracetamol]] (acetaminophen)-induced liver injury in mice.<ref name="PMID20962895">{{cite journal |vauthors=Kelava T, Cavar I, Čulo F | title = Influence of small doses of various drug vehicles on acetaminophen-induced liver injury | journal = Can J Physiol Pharmacol | volume = 88 | issue = 10 | pages = 980–87 |date=Oct 2010 | doi = 10.1139/Y10-065| pmid = 20962895}}</ref>

DMSO is finding increased use in manufacturing processes to produce microelectronic devices.<ref>{{cite journal|vauthors = Kvakovszky G, McKim AS, Moore J| year = 2007| title = A Review of Microelectronic Manufacturing Applications Using DMSO-Based Chemistries| journal = [[The Electrochemical Society|ECS Transactions]]| volume = 11| issue = 2| pages = 227–234| doi = 10.1149/1.2779383| bibcode = 2007ECSTr..11b.227K| s2cid = 137979405}}</ref> It is widely used to strip photoresist in TFT-LCD 'flat panel' displays and advanced packaging applications (such as wafer-level packaging / solder bump patterning). DMSO is an effective [[paint stripper]], being safer than many of the others such as [[nitromethane]] and [[dichloromethane]].

===Biology===
DMSO is used in [[polymerase chain reaction]] (PCR) to inhibit [[Stem-loop|secondary structures]] in the [[DNA#Polymerases|DNA template]] or the [[DNA primer]]s. It is added to the PCR mix before reacting, where it interferes with the self-complementarity of the DNA, minimizing interfering reactions.<ref>

{{cite journal
| vauthors = Chakrabarti R, Schutt CE
| date=August 2001
| title = The enhancement of PCR amplification by low molecular-weight sulfones
| journal = [[Gene (journal)|Gene]]
| volume = 274
| issue = 1–2
| pages = 293–298
| pmid = 11675022
| doi = 10.1016/S0378-1119(01)00621-7
}}
</ref>

DMSO in a PCR is applicable for supercoiled plasmids (to relax before amplification) or DNA templates with high [[GC-content]] (to decrease [[thermostability]]). For example, 10% final concentration of DMSO in the PCR mixture with Phusion decreases primer annealing temperature (i.e. primer melting temperature) by {{convert|5.5|–|6.0|C-change|F-change}}.<ref>{{cite web|url=https://www.neb.com/protocols/2012/06/01/guidelines-for-pcr-optimization-with-phusion-high-fidelity-dna-polymerase | title = Guidelines for PCR Optimization with Phusion High-Fidelity DNA Polymerase}}</ref>

It is well known as a reversible cell cycle arrester at phase G1 of human lymphoid cells.<ref>
{{cite journal
| vauthors = Sawai M, Takase K, Teraoka H, Tsukada K
| title = Reversible G1 arrest in the cell cycle of human lymphoid cell lines by dimethyl sulfoxide
| year = 1990
| journal = Exp. Cell Res.
| volume = 187
| issue = 1
| pages = 4–10
| pmid = 2298260
| doi=10.1016/0014-4827(90)90108-m
}}
</ref>

DMSO may also be used as a [[cryoprotectant]], added to cell media to reduce ice formation and thereby prevent cell death during the freezing process.<ref>
{{cite book
| vauthors = Pegg, DE
|title=Cryopreservation and Freeze-Drying Protocols |veditors=Day JG, Stacey GN | year = 2007
| chapter = Principles of Cryopreservation
| journal = Cryopreservation and Freeze-Drying Protocols, Second Edition
| volume = 368
| series = Methods in Molecular Biology
| pages = 39–57
| publisher = Humana Press
| issn = 1064-3745
| pmid = 18080461
| doi = 10.1007/978-1-59745-362-2_3
| isbn = 978-1-58829-377-0
}}
</ref> Approximately 10% may be used with a slow-freeze method, and the cells may be frozen at {{convert|−80|C|F}} or stored in [[liquid nitrogen]] safely.

In cell culture, DMSO is used to induce [[Cellular differentiation|differentiation]] of [[P19 embryonic carcinoma cell]]s into [[cardiomyocyte]]s and [[skeletal muscle cell]]s.

===Medicine===
Use of DMSO in medicine dates from around 1963, when an [[Oregon Health & Science University]] Medical School team, headed by [[Stanley Jacob]], discovered it could penetrate the skin and other membranes without damaging them and could carry other compounds into a biological system. In medicine, DMSO is predominantly used as a topical [[analgesic]], a vehicle for topical application of pharmaceuticals, as an [[anti-inflammatory]], and an [[antioxidant]].<ref>{{cite book |author=Johannes Geiss |title=The century of space science |url=https://books.google.com/books?id=22FJysl__WcC&pg=PA20 |publisher=Kluwer Academic |year=2001 |page=20 |isbn=978-0-7923-7195-3|access-date=2011-08-07}}</ref> Because DMSO increases the rate of absorption of some compounds through [[biological tissue]]s, including [[skin]], it is used in some [[transdermal]] [[drug delivery]] systems.  Its effect may be enhanced with the addition of [[EDTA]]. It is frequently compounded with antifungal medications, enabling them to penetrate not just skin but also toenails and fingernails.<ref>{{cite journal | vauthors = Capriotti K, Capriotti JA | title = Onychomycosis treated with a dilute povidone-iodine/dimethyl sulfoxide preparation | journal = International Medical Case Reports Journal | volume = 8 | pages = 231–233 | date = 2015-10-08 | pmid = 26491374 | pmc = 4599634 | doi = 10.2147/IMCRJ.S90775 | doi-access = free }}</ref>

DMSO has been examined for the treatment of numerous conditions and ailments, but the U.S. [[Food and Drug Administration]] (FDA) has approved its use only for the symptomatic relief of patients with [[interstitial cystitis]].<ref>{{Cite web|url=http://www.accessdata.fda.gov/cms_ia/importalert_169.html|title=Import Alert 62-06|website=www.accessdata.fda.gov|access-date=2017-03-05|archive-url=https://web.archive.org/web/20170204023101/http://www.accessdata.fda.gov/cms_ia/importalert_169.html|archive-date=2017-02-04|url-status=dead}}</ref> A 1978 study concluded that DMSO brought [[statistical significance|significant]] relief to the majority of the 213&nbsp;patients with inflammatory [[genitourinary]] disorders that were studied.<ref>
{{cite journal
| vauthors = Shirley SW, Stewart BH, Mirelman S
| date=March 1978
| title = Dimethyl Sulfoxide in Treatment of Inflammatory Genitourinary Disorders
| journal = [[Urology (journal)|Urology]]
| volume = 11
| issue = 3
| pages = 215–220
| pmid = 636125
| doi = 10.1016/0090-4295(78)90118-8
| url = http://www.dmso.org/articles/bladder/bladder1.htm
}}
</ref> The authors recommended DMSO for genitourinary inflammatory conditions not caused by infection or tumor in which symptoms were severe or patients failed to respond to conventional therapy.

In [[interventional radiology]], DMSO is used as a solvent for [[EVOH|ethylene vinyl alcohol]] in the [[Onyx (Interventional radiology)|Onyx]] liquid embolic agent, which is used in [[embolization]], the therapeutic occlusion of blood vessels.

In [[cryobiology]] DMSO has been used as a [[cryoprotectant]] and is still an important constituent of cryoprotectant [[Cryopreservation#Vitrification|vitrification]] mixtures used to preserve organs, tissues, and cell suspensions. Without it, up to 90% of frozen cells will become inactive. It is particularly important in the freezing and long-term storage of [[embryonic stem cells]] and [[hematopoietic stem cell]]s, which are often frozen in a mixture of 10%&nbsp;DMSO, a freezing medium, and 30% [[fetal bovine serum]]. In the cryogenic freezing of heteroploid cell lines ([[MDCK]], [[Vero cell|VERO]], etc.) a mixture of 10%&nbsp;DMSO with 90%&nbsp;[[EMEM]] (70%&nbsp;EMEM + 30%&nbsp;fetal bovine serum + antibiotic mixture) is used. As part of an [[autologous]] [[bone marrow transplant]] the DMSO is re-infused along with the patient's own [[hematopoietic stem cell]]s.

DMSO is metabolized by [[disproportionation]] to [[dimethyl sulfide]] and [[dimethyl sulfone]]. It is subject to renal and pulmonary excretion. A possible side effect of DMSO is therefore elevated blood dimethyl sulfide, which may cause a blood borne [[halitosis]] symptom.

===Alternative medicine===
DMSO is marketed as an [[alternative medicine]]. Its popularity as an alternative cure is stated to stem from a ''[[60 Minutes]]'' documentary in 1980 featuring an early proponent.<ref name=NCAHF>{{cite web|url = https://quackwatch.org/ncahf/articles/c-d/dmso/|title= DMSO |publisher = [[National Council Against Health Fraud]]| vauthors = Jarvis WT |date = 24 November 2001 |access-date=19 July 2022}}</ref> However, DMSO is an ingredient in some products listed by the U.S. FDA as fake cancer cures<ref name="FDA-fake">{{cite web|archive-url = https://web.archive.org/web/20170723111430/https://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/EnforcementActivitiesbyFDA/ucm171057.htm |title =187 Fake Cancer "Cures" Consumers Should Avoid|website = FDA|url = https://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/EnforcementActivitiesbyFDA/ucm171057.htm|url-status = dead|archive-date = 23 July 2017}}</ref> and the FDA has had a running battle with distributors.<ref name=NCAHF /> One such distributor is Mildred Miller, who promoted DMSO for a variety of disorders and was consequently convicted of [[Medicare fraud]].<ref name=NCAHF />

The use of DMSO as an alternative treatment for cancer is of particular concern, as it has been shown to interfere with a variety of [[chemotherapy]] drugs, including [[cisplatin]], [[carboplatin]], and [[oxaliplatin]].<ref>{{cite journal | vauthors = Hall MD, Telma KA, Chang KE, Lee TD, Madigan JP, Lloyd JR, Goldlust IS, Hoeschele JD, Gottesman MM | display-authors = 6 | title = Say no to DMSO: dimethylsulfoxide inactivates cisplatin, carboplatin, and other platinum complexes | journal = Cancer Research | volume = 74 | issue = 14 | pages = 3913–3922 | date = July 2014 | pmid = 24812268 | pmc = 4153432 | doi = 10.1158/0008-5472.CAN-14-0247 }}</ref> There is insufficient evidence to support the hypothesis that DMSO has any effect,<ref name="Saling 2022">{{cite web | last=Saling | first=Joseph | title=DMSO: Uses and Risks | website=[[WebMD]] | date=20 June 2022 | url=https://www.webmd.com/vitamins-and-supplements/dmso-uses-and-risks | access-date=19 July 2022}}</ref> and most sources agree that its history of side effects when tested warrants caution when using it as a dietary supplement, for which it is marketed heavily with the [[quack Miranda warning|usual disclaimer]].

===Veterinary medicine===
DMSO is commonly used in veterinary medicine as a [[liniment]] for [[horse]]s, alone or in combination with other ingredients.  In the latter case, often, the intended function of the DMSO is as a solvent, to carry the other ingredients across the skin.  Also in horses, DMSO is used intravenously, again alone or in combination with other drugs.  It is used alone for the treatment of increased intracranial pressure and/or cerebral edema in horses.{{fact|date=July 2022}}

===Taste===
The perceived garlic taste upon skin contact with DMSO may be due to [[olfaction|nonolfactory]] activation of [[Transient receptor potential cation channel, member A1|TRPA1]] receptors in [[trigeminal ganglia]].<ref>{{cite journal | vauthors = Lübbert M, Kyereme J, Schöbel N, Beltrán L, Wetzel CH, Hatt H | title = Transient receptor potential channels encode volatile chemicals sensed by rat trigeminal ganglion neurons | journal = PLOS ONE | volume = 8 | issue = 10 | pages = e77998 | date = October 21, 2013 | pmid = 24205061 | pmc = 3804614 | doi = 10.1371/journal.pone.0077998 | doi-access = free | bibcode = 2013PLoSO...877998L }}</ref>  Unlike [[dimethyl disulfide|dimethyl]] and [[diallyl disulfide|diallyl]] disulfides (which have odors resembling garlic), [[dimethyl sulfide|mono-]] and [[dimethyl trisulfide|tri-]] sulfides (which typically have foul odors), and similar odiferous sulfur compounds, the pure chemical DMSO is odorless.

==Safety==

===Toxicity===
DMSO is a non-toxic solvent with a [[median lethal dose]] higher than ethanol (DMSO: LD<sub>50</sub>, oral, rat, 14,500&nbsp;mg/kg;<ref>{{Cite web |date=21 July 2016 |title=Safety Data Sheet: Dimethyl Sulfoxide (DMSO) |url=https://www.gaylordchemical.com/wp-content/uploads/2017/05/Dimethyl-Sulfoxide-DMSO-OSHA-WHMIS-GHS-SDS-2016-07-21-002.pdf?x81144 |url-status=live |archive-url=https://web.archive.org/web/20190213175640/https://www.gaylordchemical.com/wp-content/uploads/2017/05/Dimethyl-Sulfoxide-DMSO-OSHA-WHMIS-GHS-SDS-2016-07-21-002.pdf?x81144 |archive-date=13 February 2019 |publisher=Gaylord Chemical Company, L.L.C.}}</ref><ref>{{Cite web |date=21 May 2013 |title=Material Safety Data Sheet: Dimethyl Sulfoxide |url=http://www.sciencelab.com/msds.php?msdsId=9927347 |url-status=dead |archive-url=https://web.archive.org/web/20180919061701/http://www.sciencelab.com/msds.php?msdsId=9927347 |archive-date=19 September 2018 |website=ScienceLab.com}}</ref> ethanol: LD<sub>50</sub>, oral, rat, 7,060&nbsp;mg/kg<ref>{{Cite web |date=21 May 2013 |title=Material Safety Data Sheet: Ethyl alcohol 200 Proof |url=http://www.sciencelab.com/msds.php?msdsId=9923955 |url-status=dead |archive-url=https://web.archive.org/web/20180919024836/http://www.sciencelab.com/msds.php?msdsId=9923955 |archive-date=19 September 2018 |website=ScienceLab.com}}</ref>).

DMSO can cause contaminants, toxins, and medicines to be absorbed through the skin, which may cause unexpected effects. DMSO is thought to increase the effects of blood thinners, steroids, heart medicines, sedatives, and other drugs. In some cases this could be harmful or dangerous.<ref name="ACS">{{Cite web |title=DMSO |url=http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/pharmacologicalandbiologicaltreatment/dmso |url-status=dead |archive-url=https://web.archive.org/web/20100727042310/http://www.cancer.org/treatment/treatmentsandsideeffects/complementaryandalternativemedicine/pharmacologicalandbiologicaltreatment/dmso |archive-date=27 July 2010 |publisher=[[American Cancer Society]]}}</ref>

Because DMSO easily penetrates the [[skin]], substances dissolved in DMSO may quickly be absorbed. [[Glove]] selection is important when working with DMSO. [[Butyl rubber]], [[fluoroelastomer]], [[neoprene]], or thick (15{{nbsp}}[[mil (imperial)|mil]] / 0.4{{nbsp}}[[millimetre|mm]]) [[latex]] gloves are recommended.<ref>[http://mykin.com/rubber-chemical-resistance-chart-2 Rubber Chemical Resistance Chart]</ref> [[Nitrile rubber|Nitrile]] gloves, which are very commonly used in chemical laboratories, may protect from brief contact but have been found to degrade rapidly with exposure to DMSO.<ref>{{Cite web |date=October 1999 |title=Chemical hygiene plan |url=http://people.ccmr.cornell.edu/~cober/complete.chemical.hygiene.plan.2000.pdf |access-date=2010-04-12 |publisher=[[Cornell University]]}}</ref>

=== Regulation ===

In Australia, it is listed as a [[Standard for the Uniform Scheduling of Medicines and Poisons|Schedule 4 (S4)]] Drug, and a company has been prosecuted for adding it to products as a preservative.<ref>{{Cite web |date=23 April 2003 |title=Brisbane drug company convicted of counterfeiting |url=http://www.health.gov.au/internet/main/publishing.nsf/Content/health-mediarel-yr2003-tw-tw03009.htm |url-status=dead |archive-url=https://web.archive.org/web/20120321234044/http://www.health.gov.au/internet/main/publishing.nsf/Content/health-mediarel-yr2003-tw-tw03009.htm |archive-date=2012-03-21 |publisher=Commonwealth of Australia: Department of Health and Ageing}}</ref>

=== Clinical safety ===

Early clinical trials with DMSO were stopped because of questions about its safety, especially its ability to harm the eye. The most commonly reported side effects include headaches and burning and itching on contact with the skin. Strong allergic reactions have been reported.{{full citation needed|date=January 2013}}

On September 9, 1965, ''[[The Wall Street Journal]]'' reported that a manufacturer of the chemical warned that the death of an Irish woman after undergoing DMSO treatment for a sprained wrist may have been due to the treatment, although no autopsy was done, nor was a causal relationship established.<ref>{{Cite news |date=September 9, 1965 |title=DMSO may have caused death of woman, makers of 'Wonder' drug warn doctors |work=[[The Wall Street Journal]] |location=New York City |vauthors=Carley W}}</ref> [[Clinical research]] using DMSO was halted and did not begin again until the [[National Academy of Sciences]] (NAS) published findings in favor of DMSO in 1972.<ref name="fda.gov">https://www.fda.gov/ForIndustry/ImportProgram/ImportAlerts/ucm162294.htm {{Dead link|date=April 2010}}</ref>  In 1978, the US FDA approved DMSO for treating [[interstitial cystitis]].  In 1980, the US Congress held hearings on claims that the FDA was slow in approving DMSO for other medical uses.  In 2007, the US FDA granted "fast track" designation on clinical studies of DMSO's use in reducing brain tissue swelling following [[traumatic brain injury]].<ref name="fda.gov" />

DMSO exposure to developing mouse brains can produce brain degeneration. This [[neurotoxicity]] could be detected at [[dose (biochemistry)|dose]]s as low as 0.3{{nbsp}}mL/kg, a level exceeded in children exposed to DMSO during [[bone marrow transplant]].<ref>{{Cite journal |vauthors=Hanslick JL, Lau K, Noguchi KK, Olney JW, Zorumski CF, Mennerick S, Farber NB |date=April 2009 |title=Dimethyl sulfoxide (DMSO) produces widespread apoptosis in the developing central nervous system |journal=Neurobiology of Disease |volume=34 |issue=1 |pages=1–10 |doi=10.1016/j.nbd.2008.11.006 |pmc=2682536 |pmid=19100327}}</ref>

===Odor problem===
DMSO disposed into [[sanitary sewer|sewers]] can cause odor problems in municipal effluents: waste water [[bacteria]] transform DMSO under [[Hypoxia (environmental)|hypoxic]] (anoxic) conditions into [[dimethyl sulfide]] (DMS) that has a strong disagreeable odor, similar to rotten cabbage.<ref>{{Cite journal |vauthors=Glindemann D, Novak J, Witherspoon J |date=January 2006 |title=Dimethyl sulfoxide (DMSO) waste residues and municipal waste water odor by dimethyl sulfide (DMS): the North-East WPCP plant of Philadelphia |journal=Environmental Science and Technology |volume=40 |issue=1 |pages=202–207 |bibcode=2006EnST...40..202G |doi=10.1021/es051312a |pmid=16433352}}</ref> However, chemically pure DMSO is odorless because of the lack of C-S-C ([[Sulfide#Organic chemistry|sulfide]]) and C-S-H ([[thiol|mercaptan]]) linkages. Deodorization of DMSO is achieved by removing the odorous impurities it contains.<ref>{{cite patent|invent1=George Kvakovszky |invent2=David Villarrubia II|invent3=Scott Stevenson|invent4=Charles G. Ashe|title=Process for preparing low malodorous dimethyl sulfoxide |country=US |status=application |number=2009005601A1 |assign=Gaylord Chemical Company LLC|pubdate=2009}}</ref>

===Explosion hazard===
Dimethyl sulfoxide can produce an explosive reaction when exposed to [[acyl chloride]]s; at a low temperature, this reaction produces the [[oxidizing agent|oxidant]] for [[Swern oxidation]].

DMSO can decompose at the boiling temperature of 189&nbsp;°C at normal pressure, possibly leading to an explosion. The decomposition is catalyzed by acids and bases and therefore can be relevant at even lower temperatures. A strong to explosive reaction also takes place in combination with halogen compounds, metal nitrides, metal perchlorates, sodium hydride, periodic acid and fluorinating agents.<ref>{{cite book |author1=Roth, Lutz |author2=Weller, Ursula |title=Gefährliche Chemische Reaktionen |series=Ecomed Sicherheit |publisher=Verlagsgruppe Hüthig Jehle Rehm |location=Landsberg/Lech |date=August 2000 |language=de |trans-title=Dangerous Chemical Reactions |isbn=3-609-73090-0}} CD-ROM: {{ISBN|3-609-48040-8}}</ref>

==See also==
* Varying oxidation of sulfur
** [[Dimethyl sulfide]] (DMS), the corresponding sulfide, also produced by marine phytoplankton and emitted to the oceanic atmosphere where it is oxidized to DMSO, SO<sub>2</sub> and sulfate
** Dimethyl sulfone, commonly known as [[methylsulfonylmethane]] (MSM), a related chemical often marketed as a dietary supplement
*Related compounds with methyl on oxygen
** [[Dimethyl sulfite]], the corresponding sulfite
** [[Dimethyl sulfate]] (also DMS), the corresponding sulfate: a [[mutagenic]] [[alkylation|alkylating]] compound
** [[Methyl methanesulfonate]], another methylating agent
* [[Death of Gloria Ramirez|Gloria Ramirez]], also known as the "Toxic Woman"

==References==
{{Reflist|2}}

==External links==
{{Commons category|Dimethyl sulfoxide|lcfirst=yes}}
* {{ICSC|0459}}
* [http://www.dmso.org Dimethyl Sulfoxide Information Center]

{{Urologicals}}
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{{DEFAULTSORT:Dimethyl Sulfoxide}}
[[Category:Solvents]]
[[Category:Sulfoxides]]
[[Category:Foul-smelling chemicals]]
[[Category:Methyl compounds]]