Phenol red - wikipedia Phenol red Phenol red Identifiers CAS Number 143 - 74 - 8 3D model ( JSmol ) Interactive image ChEBI CHEBI : 31991 ChemSpider 4602 ECHA InfoCard 100.005. 100 PubChem CID 4766 InChI InChI = 1S / C19H14O5S / c20 - 15 - 9 - 5 - 13 ( 6 - 10 - 15 ) 19 ( 14 - 7 - 11 - 16 ( 21 ) 12 - 8 - 14 ) 17 - 3 - 1 - 2 - 4 - 18 ( 17 ) 25 ( 22, 23 ) 24 - 19 / h1 - 12, 20 - 21H Key : BELBBZDIHDAJOR - UHFFFAOYSA - N SMILES O = S2 ( = O ) OC ( c1ccccc12 ) ( c3ccc ( O ) cc3 ) c4ccc ( O ) cc4 Properties Chemical formula Molar mass 354.38 g mol Pharmacology ATC code V04CH03 ( WHO ) Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). Y verify ( what is ? ) Infobox references Phenol red ( also known as phenolsulfonphthalein or PSP ) is a pH indicator frequently used in cell biology laboratories. Contents 1 Chemical structure and properties 2 Phenolsulfonphthalein test 3 Indicator for cell cultures 4 Estrogen mimic 5 Use in swimming pool test kits 6 References 7 External links Chemical structure and properties Phenol red exists as a red crystal that is stable in air. Its solubility is 0.77 grams per liter ( g / l ) in water and 2.9 g / l in ethanol. It is a weak acid with pK = 8.00 at 20 ° C ( 68 ° F ). A solution of phenol red is used as a pH indicator, often in cell culture. Its color exhibits a gradual transition from yellow ( λ = 443 nm ) to red ( λ = 570 nm ) over the pH range 6.8 to 8.2. Above pH 8.2, phenol red turns a bright pink ( fuchsia ) color. Phenol red ( pH indicator ) below pH 6.8 above pH 8.2 6.8 ⇌ 8.2 In crystalline form, and in solution under very acidic conditions ( low pH ), the compound exists as a zwitterion as in the structure shown above, with the sulfate group negatively charged, and the ketone group carrying an additional proton. This form is sometimes symbolically written as H + 2PS − and is orange - red. If the pH is increased ( pK = 1.2 ), the proton from the ketone group is lost, resulting in the yellow, negatively charged ion denoted as HPS. At still higher pH ( pK = 7.7 ), the phenol 's hydroxide group loses its proton, resulting in the red ion denoted as PS. In several sources, the structure of phenol red is shown with the sulfur atom being part of a cyclic group, similar to the structure of phenolphthalein. However, this cyclic structure could not be confirmed by X-ray crystallography. Several indicators share a similar structure to phenol red, including bromothymol blue, thymol blue, bromocresol purple, thymolphthalein, and phenolphthalein. ( A table of other common chemical indicators is available in the article on pH indicators. ) Phenolsulfonphthalein test Phenol red was used in the phenolsulfonphthalein test to estimate the overall blood flow through the kidney and is now obsolete. The test is based on the fact that phenol red is excreted almost entirely in the urine. Phenol red solution is administered intravenously, the urine produced is collected. By measuring the amount of phenol red excreted colorimetrically, kidney function can be determined. Indicator for cell cultures Phenol red, 40 μM : colors in cell culture medium at a pH range from 6.0 to 8.0. Most living tissues prosper at a near - neutral pH ; that is, a pH close to 7. The pH of blood ranges from 7.35 to 7.45, for instance. When cells are grown in tissue culture, the medium in which they grow is held close to this physiological pH. A small amount of phenol red added to this growth medium will have a pink - red color under normal conditions. Typically, 15 mg / l are used for cell culture. In the event of problems, waste products produced by dying cells or overgrowth of contaminants will cause a change in pH, leading to a change in indicator color. For example, a culture of relatively slowly dividing mammalian cells can be quickly overgrown by bacterial contamination. This usually results in an acidification of the medium, turning it yellow. Many biologists find this a convenient way to rapidly check on the health of tissue cultures. In addition, the waste products produced by the mammalian cells themselves will slowly decrease the pH, gradually turning the solution orange and then yellow. This color change is an indication that even in the absence of contamination, the medium needs to be replaced ( generally, this should be done before the medium has turned completely orange ). Since the color of phenol red can interfere with some spectrophotometric and fluorescent assays, many types of tissue culture media are also available without phenol red. Estrogen mimic A commercial test kit for swimming pools with phenol red and an orthotolidine indicator solution Phenol red is a weak estrogen mimic, and in cell cultures can enhance the growth of cells that express the estrogen receptor. An important breakthrough in biotechnology was reported in 2005 by Bukovsky and coworkers. Using phenol red as a differentiation factor, they produced human oocytes ( eggs ) from cells scraped from the surface of adult ovaries. These cells on the outer ovarian surface are known as ovarian surface epithelial cells. Such cells had been taken from five women aged 39 to 52 and were cultured in the presence of phenol red, inducing oogenesis. Previously, human eggs had only been produced in vitro from totipotent, blastomeric embryonic stem cells. This experiment demonstrated viable human egg cells can easily be produced from an adult cell that already has some degree of specialization. Furthermore, it lessens the implications associated with the fact that women are born with all of the egg cells they will ever have throughout their lives. While this breakthrough was not without controversy, it provides hope for infertile women wishing to undergo in vitro fertilization, and hints at the possibility of new options for postmenopausal women, as well. It also suggests the future of stem cell research may not have to rely as heavily on human embryos as a source of unspecialized, totipotent cells for research. Use in swimming pool test kits Phenol red, sometimes labelled with a different name, such as `` Guardex Solution # 2 '', is used as a pH indicator in home swimming pool test kits. Chlorine can result in the bleaching of the dye in the absence of thiosulfate to inhibit the oxidizing chlorine. High levels of bromine can convert phenol red to bromophenol red ( dibromophenolsulfonephthalein, whose lowered pK results in an indicator with a range shifted in the acidic direction -- water at pH 6.8 will appear to test at 7.5 ). Even higher levels of bromine ( > 20 ppm ) can result in the secondary conversion of bromophenol red to bromophenol blue with an even lower pK, erroneously giving the impression that the water has an extremely high pH despite being dangerously low. References Wikimedia Commons has media related to Phenol red. ^ Jump up to : Merck Index, 11th ed., 7213 Phenolsulfonphtalein Jump up ^ Saha, U. ; Mukherjea, K.K. ( 2015 ). `` Development of a multifunctional biomimicking L - cysteine based oxovanadium ( IV ) complex : synthesis, DFT calculations, bromo - peroxidation and nuclease activity ''. RSC Advances. 5 ( 114 ) : 94462 -- 94473. doi : 10.1039 / C5RA19585C. Jump up ^ Mills, A. ; Skinner, G.A. ( 2011 ). `` A novel ' fizziness ' indicator ''. The Analyst. 136 ( 5 ) : 894 -- 896. doi : 10.1039 / c0an00610f. Jump up ^ Merck Index, 13th ed., 7329 Phenolsulfonphthalein Jump up ^ Beilstein 5 - 19 - 03 - 00457 Jump up ^ Tamura, Z. ; Maeda M. ( 1997 ). `` Differences between phthaleins and sulfonphthaleins ''. Yakugaku Zasshi ( in Japanese ). 117 ( 10 -- 11 ) : 764 -- 770. PMID 9414589. Jump up ^ `` Phenolsulfonphthalein ''. PubChem. NIH. Jump up ^ Yamaguchi, K. ; Tamura, Z. ; Maeda, M. ( 1997 ). `` Molecular Structure of the Zwitterionic Form of Phenolsulfonphthalein '' ( pdf ). Analytical Sciences. 13 ( 3 ) : 521 -- 522. doi : 10.2116 / analsci. 13.521. Jump up ^ `` Phenolsulfonphthalein Test ''. Encyclopædia Britannica. Jump up ^ Berthois, Y. ; Katzenellenbogen, J.A. ; Katzenellenbogen, B.S. ( 1986 ). `` Phenol red in tissue culture media is a weak estrogen : Implications concerning the study of estrogen - responsive cells in culture '' ( pdf ). Proceedings of the National Academy of Sciences of the United States of America. 83 ( 8 ) : 2496 -- 2500. PMC 323325. PMID 3458212. doi : 10.1073 / pnas. 83.8. 2496. Jump up ^ Bukovsky, A. ; Svetlikova, M. ; Caudle, M.R. ( 2005 ). `` Oogenesis in Cultures Derived from Adult Human Ovaries '' ( pdf ). Reproductive Biology and Endocrinology. 3 ( 5 ) : 17. PMC 1131924. PMID 15871747. doi : 10.1186 / 1477 - 7827 - 3 - 17. Jump up ^ Guardex Solution 2 - Phenol Red Material Safety Data Sheet Jump up ^ Effect of Bromine on Phenol Red in pH Tests External links Video of phenol red activity demonstration and medium preparation Purine receptor modulators Receptor ( ligands ) P0 ( adenine ) Agonists : 8 - Aminoadenine Adenine P1 ( adenosine ) Agonists : 2 - ( 1 - Hexynyl ) - N - methyladenosine 2 - Cl - IB - MECA 2 ' - MeCCPA 4 ' - O - β - D - Glucosyl - 9 - O - ( 6 ' ' - deoxysaccharosyl ) olivil 5 ' - N - ethylcarboxamidoadenosine Adenosine ADP AMP Apadenoson ATL - 146e ATP BAY 60 -- 6583 Binodenoson Capadenoson CCPA CGS - 21680 CP - 532,903 Evodenoson GR 79236 LUF - 5835 LUF - 5845 N - Cyclopentyladenosine Namodenoson Neladenoson dalanate Piclidenoson Regadenoson SDZ WAG 994 Selodenoson Sonedenoson Tecadenoson UK - 432,097 Antagonists : 8 - Chlorotheophylline 8 - Phenyl - 1, 3 - dipropylxanthine 8 - Phenyltheophylline Acefylline Aminophylline ATL - 444 Bamifylline Cafedrine Caffeine Caffeine citrate Cartazolate CGH - 2466 CGS - 15943 Choline theophyllinate CPX CVT - 6883 Dimethazan DMPX DPCPX Dyphylline Enprofylline Etazolate Fenethylline IBMX Isovaleric acid Istradefylline KF - 26777 MRE3008F20 MRS - 1220 MRS - 1334 MRS - 1706 MRS - 1754 MRS - 3777 Paraxanthine Pentoxifylline Preladenant Propentofylline Proxyphylline PSB - 10 PSB - 11 PSB - 36 PSB - 603 PSB - 788 PSB - 1115 Reversine Rolofylline SCH - 442,416 SCH - 58261 Theacrine Theobromine Theodrenaline Theophylline Tozadenant Tracazolate VUF - 5574 ZM - 241,385 P2 ( nucleotide ) P2X ( ATP ) Agonists : 2 - Me - SATP α, β - Me - ATP Adenosine ADP AMP Ap4A Ap5A ATP ATPγS BzATP Cibacron blue CTP D - β, γ - Me - ATP GTP HT - AMP Ivermectin L - β, γ - Me - ATP MRS - 2219 PAPET - ATP UTP Zinc Antagonists : 5 - BDBD A-317491 A-438079 A-740003 A-804598 A-839977 AF - 353 AZ - 10606120 AZ - 11645373 BBG Calcium Calmidazolium Chelerythrine Copper Emodin ( Rheum officinale ) Evans Blue GW - 791343 HMA Ip5I isoPPADS JNJ - 47965567 KN - 04 KN - 62 Magnesium MRS - 2159 NF - 023 NF - 110 NF - 157 NF - 279 NF - 449 Oxidized - ATP Phenol Red Phenolphthalein PPADS PPNDS PSB - 12062 Puerarin ( Radix puerariae ) Purotoxin 1 RB - 2 Ro 0437626 Ro 51 RO - 3 Sodium ferulate ( Angelica sinensis, Ligusticum wallichii ) Suramin TC - P 262 Tetramethylpyrazine ( ligustrazine ) ( Ligusticum wallichii ) TNP - ATP Zinc P2Y Agonists : 2 - Me - SADP 2 - Me - SATP 2 - Thio - UTP 5 - Br - UDP 5 - OMe - UDP α, β - Me - ATP Adenosine ADP ADPβS Ap3A AR - C 67085MX ATP ATPγS CTP dATP Denufosol Diquafosol IDP ITP INS - 365 INS - 37217 MRS - 2365 MRS - 2690 MRS - 2693 MRS - 2768 MRS - 2957 MRS - 4062 NF - 546 PAPET - ATP PSB - 0474 PSB - 1114 UDP UDPβS UDP - galactose UDP - glucose UDP - N - acetylglucosamine Up3U UTP UTPγS Antagonists : 2 - Me - SAMP A3P5PS AMPαS Ap4A AR - C 66096 AR - C 67085MX AR - C 69931MX AR - C 118925XX ATP BzATP C1330 - 7 Cangrelor Clopidogrel Elinogrel Ip5I MRS - 2179 MRS - 2211 MRS - 2279 MRS - 2395 MRS - 2500 MRS - 2578 NF - 157 NF - 340 PIT PPADS Prasugrel PSB - 0739 RB - 2 Regrelor Suramin Ticagrelor Ticlopidine UDP Transporter ( blockers ) CNTs 6 - Hydroxy - 7 - methoxyflavone Adenosine dMeThPmR Estradiol KGO - 2142 KGO - 2173 MeThPmR Phloridzin Progesterone ENTs Barbiturates Benzodiazepines Cilostazol Dilazep Dipyridamole Estradiol Ethanol Hexobendine NBMPR Pentoxifylline Progesterone Propentofylline PMAT Decynium - 22 Enzyme ( inhibitors ) XO Allopurinol Amflutizole Benzbromarone Caffeic acid Cinnamaldehyde Cinnamomum osmophloeum Febuxostat Myo - inositol Kaempferol Myricetin Niraxostat Oxipurinol Phytic acid Pistacia integerrima Propolis Quercetin Tisopurine Topiroxostat Others Aminopterin Azathioprine Methotrexate Mycophenolic acid Pemetrexed Pralatrexate Many others Others Precursors : Adenine Adenosine AMP ADP ATP Cytosine Cytidine CMP CDP CTP Guanine Guanosine GMP GDP GTP Hypoxanthine Inosine IMP IDP ITP Ribose Uracil Uridine UMP UDP UTP Others : Chrysophanol ( rhubarb ) See also : Receptor / signaling modulators Retrieved from `` https://en.wikipedia.org/w/index.php?title=Phenol_red&oldid=799516656 '' Categories : PH indicators Triarylmethane dyes Phenols Benzenesulfonates Hidden categories : CS1 Japanese - language sources ( ja ) Articles without InChI source Articles without KEGG source Articles without UNII source ECHA InfoCard ID from Wikidata Articles containing unverified chemical infoboxes All articles with unsourced statements Articles with unsourced statements from February 2011 Use dmy dates from February 2011 Talk Contents About Wikipedia Deutsch Español Esperanto Français Italiano Nederlands 日本 語 Polski Português Русский Српски / srpski Srpskohrvatski / српскохрватски Suomi Türkçe Edit links This page was last edited on 8 September 2017, at 05 : 22. 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Question: what is the color of phenol red at an acid ph
Answer: bright pink (fuchsia) color