A colour indicator that possesses a different colour on each side of the transition interval.
| Member | Definition | Class |
|---|
| bromcresol purple | A member of the class of 2,1-benzoxathioles that is 2,1-benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 3-bromo-4-hydroxy-5-methylphenyl groups. A hydrophilic dye that is used as a pH indicator and to measure serum albumin concentrations. | bromocresol purple |
| bromphenol blue | 3H-2,1-Benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 3,5-dibromo-4-hydroxyphenyl groups. It is used as a laboratory indicator, changing from yellow below pH 3 to purple at pH 4.6, and as a size marker for monitoring the progress of agarose gel and polyacrylamide gel electrophoresis. It has also been used as an industrial dye. | bromophenol blue |
| bromthymol blue | A member of the class of 2,1-benzoxathioles that is 2,1-benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 3-bromo-4-hydroxy-5-isopropyl-2-methylphenyl groups. | bromothymol blue |
| cobaltous chloride | A cobalt salt in which the cobalt metal is in the +2 oxidation state and the counter-anion is chloride. It is used as an indicator for water in desiccants. | cobalt dichloride |
| cresol red | A member of the class of 2,1-benzoxathioles that is 2,1-benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 4-hydroxy-5-methylphenyl groups. | cresol red |
| neutral red | A hydrochloride obtained by combining the free base of neutral red with one equivalent of hydrochloric acid. Neutral red acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0. | neutral red |
| neutral red base | A member of the class of phenazines carrying methyl, amino and dimethylamino substituents at positions 2, 3 and 7 respectively. The free base of neutral red, which acts as a pH indicator, changing from red to yellow between pH 6.8 and 8.0. | neutral red base |
| phenolsulfonphthalein | 3H-2,1-Benzoxathiole 1,1-dioxide in which both of the hydrogens at position 3 have been substituted by 4-hydroxyphenyl groups. A pH indicator changing colour from yellow below pH 6.8 to bright pink above pH 8.2, it is commonly used as an indicator in cell cultures and in home swimming pool test kits. It is also used in the (now infrequently performed) phenolsulfonphthalein (PSP) test for estimation of overall blood flow through the kidney. | phenol red |
| Protein | Taxonomy | Measurement | Average (mM) | Bioassay(s) | Drugs |
|---|
| activating transcription factor 6 | Homo sapiens (human) | Potency | 44.9498 | 2 | 3 |
| apical membrane antigen 1, AMA1 | Plasmodium falciparum 3D7 | Potency | 2.8184 | 1 | 1 |
| AR protein | Homo sapiens (human) | Potency | 13.7424 | 5 | 5 |
| Ataxin-2 | Homo sapiens (human) | Potency | 12.5386 | 1 | 1 |
| ATPase family AAA domain-containing protein 5 | Homo sapiens (human) | Potency | 12.5386 | 1 | 1 |
| caspase 7, apoptosis-related cysteine protease | Homo sapiens (human) | Potency | 35.3385 | 1 | 1 |
| caspase-3 | Homo sapiens (human) | Potency | 35.3385 | 1 | 1 |
| Chain A, JmjC domain-containing histone demethylation protein 3A | Homo sapiens (human) | Potency | 50.1187 | 1 | 1 |
| cytochrome P450 2C9 precursor | Homo sapiens (human) | Potency | 6.3096 | 1 | 1 |
| cytochrome P450 2C9, partial | Homo sapiens (human) | Potency | 1.9497 | 1 | 1 |
| cytochrome P450 family 3 subfamily A polypeptide 4 | Homo sapiens (human) | Potency | 24.5454 | 1 | 1 |
| cytochrome P450, family 19, subfamily A, polypeptide 1, isoform CRA_a | Homo sapiens (human) | Potency | 22.2971 | 1 | 1 |
| DNA polymerase eta isoform 1 | Homo sapiens (human) | Potency | 50.1187 | 1 | 1 |
| DNA polymerase iota isoform a (long) | Homo sapiens (human) | Potency | 15.7142 | 1 | 2 |
| DNA polymerase kappa isoform 1 | Homo sapiens (human) | Potency | 3.1623 | 1 | 1 |
| estrogen nuclear receptor alpha | Homo sapiens (human) | Potency | 25.4196 | 7 | 11 |
| estrogen receptor 2 (ER beta) | Homo sapiens (human) | Potency | 70.5096 | 1 | 1 |
| estrogen-related nuclear receptor alpha | Homo sapiens (human) | Potency | 33.2545 | 6 | 9 |
| euchromatic histone-lysine N-methyltransferase 2 | Homo sapiens (human) | Potency | 17.7828 | 1 | 1 |
| flap endonuclease 1 | Homo sapiens (human) | Potency | 28.5991 | 1 | 2 |
| G | Vesicular stomatitis virus | Potency | 1.9497 | 1 | 1 |
| GLI family zinc finger 3 | Homo sapiens (human) | Potency | 5.5856 | 2 | 2 |
| glp-1 receptor, partial | Homo sapiens (human) | Potency | 22.3872 | 1 | 1 |
| GLS protein | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| Glutamate receptor 2 | Rattus norvegicus (Norway rat) | Potency | 24.1746 | 1 | 2 |
| Histamine H2 receptor | Cavia porcellus (domestic guinea pig) | Potency | 6.3096 | 1 | 3 |
| histone deacetylase 9 isoform 3 | Homo sapiens (human) | Potency | 3.6189 | 2 | 2 |
| Histone H2A.x | Cricetulus griseus (Chinese hamster) | Potency | 39.4207 | 2 | 4 |
| HLA class I histocompatibility antigen, B alpha chain | Homo sapiens (human) | Potency | 1.9497 | 1 | 1 |
| hypothetical protein, conserved | Trypanosoma brucei | Potency | 35.4813 | 1 | 1 |
| hypoxia-inducible factor 1, alpha subunit (basic helix-loop-helix transcription factor) | Homo sapiens (human) | Potency | 0.1995 | 2 | 2 |
| Inositol hexakisphosphate kinase 1 | Homo sapiens (human) | Potency | 1.9497 | 1 | 2 |
| Interferon beta | Homo sapiens (human) | Potency | 1.9497 | 1 | 1 |
| lamin isoform A-delta10 | Homo sapiens (human) | Potency | 35.4813 | 1 | 1 |
| lethal factor (plasmid) | Bacillus anthracis str. A2012 | Potency | 2.5119 | 1 | 1 |
| Luciferase | Photinus pyralis (common eastern firefly) | Potency | 14.1447 | 2 | 4 |
| nuclear factor erythroid 2-related factor 2 isoform 2 | Homo sapiens (human) | Potency | 4.6109 | 1 | 1 |
| nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (p105), isoform CRA_a | Homo sapiens (human) | Potency | 24.5412 | 1 | 1 |
| nuclear receptor subfamily 1, group I, member 3 | Homo sapiens (human) | Potency | 23.0532 | 3 | 3 |
| parathyroid hormone/parathyroid hormone-related peptide receptor precursor | Homo sapiens (human) | Potency | 112.2020 | 1 | 1 |
| peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 | Homo sapiens (human) | Potency | 39.8107 | 1 | 1 |
| peripheral myelin protein 22 | Rattus norvegicus (Norway rat) | Potency | 10.1815 | 1 | 1 |
| peroxisome proliferator activated receptor gamma | Homo sapiens (human) | Potency | 10.0487 | 1 | 1 |
| plasminogen precursor | Mus musculus (house mouse) | Potency | 28.1838 | 1 | 1 |
| pregnane X nuclear receptor | Homo sapiens (human) | Potency | 5.6008 | 1 | 1 |
| Rap guanine nucleotide exchange factor 3 | Homo sapiens (human) | Potency | 100.0000 | 1 | 1 |
| RAR-related orphan receptor gamma | Mus musculus (house mouse) | Potency | 4.6720 | 2 | 2 |
| retinoic acid nuclear receptor alpha variant 1 | Homo sapiens (human) | Potency | 28.4580 | 3 | 3 |
| retinoid X nuclear receptor alpha | Homo sapiens (human) | Potency | 17.8693 | 1 | 1 |
| serine/threonine-protein kinase PLK1 | Homo sapiens (human) | Potency | 0.8437 | 1 | 1 |
| TDP1 protein | Homo sapiens (human) | Potency | 17.5886 | 2 | 2 |
| thyroid hormone receptor beta isoform 2 | Rattus norvegicus (Norway rat) | Potency | 28.6194 | 2 | 2 |
| thyroid stimulating hormone receptor | Homo sapiens (human) | Potency | 17.6034 | 5 | 5 |
| transcriptional regulator ERG isoform 3 | Homo sapiens (human) | Potency | 31.6228 | 1 | 1 |
| urokinase plasminogen activator surface receptor precursor | Mus musculus (house mouse) | Potency | 28.1838 | 1 | 1 |
| urokinase-type plasminogen activator precursor | Mus musculus (house mouse) | Potency | 28.1838 | 1 | 1 |
| USP1 protein, partial | Homo sapiens (human) | Potency | 42.8000 | 2 | 2 |
| vitamin D3 receptor isoform VDRA | Homo sapiens (human) | Potency | 23.6088 | 5 | 5 |
| Voltage-dependent calcium channel gamma-2 subunit | Mus musculus (house mouse) | Potency | 24.1746 | 1 | 2 |
| WRN | Homo sapiens (human) | Potency | 50.1187 | 1 | 1 |