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Redox indicator
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<h2 id="ph-independent">pH independent</h2> <table><tbody><tr><th>Indicator</th><th>E0, V</th><th>Color of Oxidized form</th><th>Color of Reduced form</th></tr><tr><td><a href="/facts/2%2c2%2527-bipyridine/3br0q27A">2,2'-bipyridine</a> (Ru complex)</td><td>+1.33</td><td>colorless</td><td>yellow</td></tr><tr><td>Nitro<a href="/facts/Phenanthroline/WAKnx70S">phenanthroline</a> (Fe complex)</td><td>+1.25</td><td>cyan</td><td>red</td></tr><tr><td>N-<a href="/facts/Phenylanthranilic_acid/2TMhJYaS">Phenylanthranilic acid</a></td><td>+1.08</td><td>violet-red</td><td>colorless</td></tr><tr><td>1,10-Phenanthroline iron(II) sulfate complex (<a href="/facts/Ferroin/coQ0rPo8">Ferroin</a>)</td><td>+1.06</td><td>cyan</td><td>red</td></tr><tr><td>N-Ethoxychrysoidine</td><td>+1.00</td><td>red</td><td>yellow</td></tr><tr><td>2,2`-<a href="/facts/Bipyridine/C2pcpnlb">Bipyridine</a> (Fe complex)</td><td>+0.97</td><td>cyan</td><td>red</td></tr><tr><td>5,6-Dimethyl<a href="/facts/Phenanthroline/WAKnx70S">phenanthroline</a> (Fe complex)</td><td>+0.97</td><td>yellow-green</td><td>cyan</td></tr><tr><td><a href="/facts/O-Dianisidine/Dg19Yvuh">o-Dianisidine</a></td><td>+0.85</td><td>red</td><td>colorless</td></tr><tr><td>Sodium diphenylamine sulfonate</td><td>+0.84</td><td>red-violet</td><td>colorless</td></tr><tr><td>Diphenylbenzidine</td><td>+0.76</td><td>violet</td><td>colorless</td></tr><tr><td><a href="/facts/Diphenylamine/CH92mQoC">Diphenylamine</a></td><td>+0.76</td><td>violet</td><td>colorless</td></tr><tr><td><a href="/facts/Viologen/uBnjDdV8">Viologen</a></td><td>-0.43</td><td>colorless</td><td>blue</td></tr></tbody></table> <h2 id="ph-dependent">pH dependent</h2> <table><tbody><tr><th>Indicator</th><th>E0, V<p>at pH=0</p></th><th>E, V<p>at pH=7</p></th><th>Color of<p>Oxidized form</p></th><th>Color of<p>Reduced form</p></th></tr><tr><td>Sodium 2,6-Dibromophenol-indophenol<p>or Sodium <a href="/facts/DCPIP/ndIFW0za">2,6-Dichlorophenol-indophenol</a></p></td><td>+0.64</td><td>+0.22</td><td>blue</td><td>colorless</td></tr><tr><td>Sodium o-Cresol <a href="/facts/Indophenol/vMhYnT7a">indophenol</a></td><td>+0.62</td><td>+0.19</td><td>blue</td><td>colorless</td></tr><tr><td><a href="/facts/Thionine/lnq0cQsL">Thionine</a> (syn. <a href="/facts/Lauth%2527s_violet/lnq0cQsL">Lauth's violet</a>)</td><td>+0.56</td><td>+0.06</td><td>violet</td><td>colorless</td></tr><tr><td><a href="/facts/Methylene_blue/NIo9Xaag">Methylene blue</a></td><td>+0.53</td><td>+0.01<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a></td><td>blue</td><td>colorless</td></tr><tr><td>Indigotetra<a href="/facts/Sulfonic_acid/6JHPGnNY">sulfonic acid</a></td><td>+0.37</td><td>-0.05</td><td>blue</td><td>colorless</td></tr><tr><td>Indigotri<a href="/facts/Sulfonic_acid/6JHPGnNY">sulfonic acid</a></td><td>+0.33</td><td>-0.08</td><td>blue</td><td>colorless</td></tr><tr><td><a href="/facts/Indigo_carmine/7owTXyQ2">Indigo carmine</a><p>(syn. Indigodi<a href="/facts/Sulfonic_acid/6JHPGnNY">sulfonic acid</a></p></td><td>+0.29</td><td>-0.13</td><td>blue</td><td>colorless</td></tr><tr><td><a href="/facts/Indigo/ICSGEsqH">Indigomono</a> <a href="/facts/Sulfonic_acid/6JHPGnNY">sulfonic acid</a></td><td>+0.26</td><td>-0.16</td><td>blue</td><td>colorless</td></tr><tr><td>Phenosafranin</td><td>+0.28</td><td>-0.25</td><td>red</td><td>colorless</td></tr><tr><td><a href="/facts/Safranin/hBhULo5h">Safranin T</a></td><td>+0.24</td><td>-0.29</td><td>red-violet</td><td>colorless</td></tr><tr><td><a href="/facts/Neutral_red/dlPzgkU2">Neutral red</a></td><td>+0.24</td><td>-0.33</td><td>red</td><td>colorless</td></tr></tbody></table> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Analytical_chemistry/MHQf3YP6">Chemical analysis</a></li> <li><a href="/facts/PH_indicator/Levp3yqq">pH indicator</a></li> <li><a href="/facts/Complexometric_indicator/vIjdmj4P">Complexometric indicator</a></li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="http://old.iupac.org/publications/pac/1978/pdf/5005x0463.pdf">Redox Indicators. Characteristics And Applications</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Ram W. Sabnis; Erwin Ross; Jutta Köthe; Renate Naumann; Wolfgang Fischer; Wilhelm-Dietrich Mayer; Gerhard Wieland; Ernest J. Newman; Charles M. Wilson (2009). "Indicator Reagents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a14_127.pub2. ISBN 978-3-527-30673-2. <a href="978-3-527-30673-2" target="_blank">978-3-527-30673-2</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>HEWITT, LF. "Oxidation-Reduction Potentials in Bacteriology and Biochemistry." Oxidation-Reduction Potentials in Bacteriology and Biochemistry. Edn 6 (1950). <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> </ol>