An acid or base which exhibits a colour change on neutralization by the basic or acidic titrant at or near the equivalence point of a titration.
| Member | Definition | Class |
|---|
| aminacrine | An aminoacridine that is acridine in which the hydrogen at position 9 is replaced by an amino group. A fluorescent dyd and topical antiseptic agent, it is used (usually as the hydrochloride salt) in eye drops for the treatment of superficial eye infections. | 9-aminoacridine |
| 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 |
| 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 |
| methylene blue | An organic chloride salt having 3,7-bis(dimethylamino)phenothiazin-5-ium as the counterion. A commonly used dye that also exhibits antioxidant, antimalarial, antidepressant and cardioprotective properties. | methylene blue |
| 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 |
|---|
| 15-hydroxyprostaglandin dehydrogenase [NAD(+)] isoform 1 | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| 67.9K protein | Vaccinia virus | Potency | 28.1838 | 2 | 2 |
| acetylcholinesterase | Homo sapiens (human) | Potency | 3.3766 | 4 | 8 |
| activating transcription factor 6 | Homo sapiens (human) | Potency | 33.8214 | 2 | 4 |
| aldehyde dehydrogenase 1 family, member A1 | Homo sapiens (human) | Potency | 28.1838 | 1 | 1 |
| alpha-galactosidase | Homo sapiens (human) | Potency | 40.0748 | 2 | 2 |
| Alpha-synuclein | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| apical membrane antigen 1, AMA1 | Plasmodium falciparum 3D7 | Potency | 2.8184 | 1 | 1 |
| AR protein | Homo sapiens (human) | Potency | 6.5713 | 7 | 16 |
| aryl hydrocarbon receptor | Homo sapiens (human) | Potency | 4.9957 | 2 | 4 |
| ATAD5 protein, partial | Homo sapiens (human) | Potency | 0.7305 | 1 | 1 |
| Ataxin-2 | Homo sapiens (human) | Potency | 13.7494 | 1 | 2 |
| ATP-dependent phosphofructokinase | Trypanosoma brucei brucei TREU927 | Potency | 37.9330 | 1 | 1 |
| ATPase family AAA domain-containing protein 5 | Homo sapiens (human) | Potency | 13.7494 | 1 | 2 |
| Bloom syndrome protein isoform 1 | Homo sapiens (human) | Potency | 31.6228 | 1 | 1 |
| bromodomain adjacent to zinc finger domain 2B | Homo sapiens (human) | Potency | 39.8107 | 1 | 1 |
| caspase 7, apoptosis-related cysteine protease | Homo sapiens (human) | Potency | 23.1046 | 1 | 2 |
| caspase-1 isoform alpha precursor | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| caspase-3 | Homo sapiens (human) | Potency | 23.1046 | 1 | 2 |
| Caspase-7 | Homo sapiens (human) | Potency | 12.5893 | 1 | 1 |
| Cellular tumor antigen p53 | Homo sapiens (human) | Potency | 11.9895 | 2 | 3 |
| Chain A, 2-oxoglutarate Oxygenase | Homo sapiens (human) | Potency | 35.7168 | 1 | 2 |
| Chain A, ATP-DEPENDENT DNA HELICASE Q1 | Homo sapiens (human) | Potency | 23.7358 | 2 | 2 |
| Chain A, Ferritin light chain | Equus caballus (horse) | Potency | 31.6228 | 1 | 2 |
| Chain A, HADH2 protein | Homo sapiens (human) | Potency | 31.6228 | 1 | 1 |
| Chain A, JmjC domain-containing histone demethylation protein 3A | Homo sapiens (human) | Potency | 47.3936 | 1 | 2 |
| Chain A, MAJOR APURINIC/APYRIMIDINIC ENDONUCLEASE | Homo sapiens (human) | Potency | 22.3872 | 1 | 1 |
| Chain A, Putative fructose-1,6-bisphosphate aldolase | Giardia intestinalis | Potency | 22.3342 | 1 | 1 |
| Chain A, TYROSYL-DNA PHOSPHODIESTERASE | Homo sapiens (human) | Potency | 41.7854 | 2 | 3 |
| Chain B, HADH2 protein | Homo sapiens (human) | Potency | 31.6228 | 1 | 1 |
| chaperonin-containing TCP-1 beta subunit homolog | Homo sapiens (human) | Potency | 22.3872 | 1 | 1 |
| cytochrome P450 2C9 precursor | Homo sapiens (human) | Potency | 6.3096 | 1 | 1 |
| cytochrome P450 2C9, partial | Homo sapiens (human) | Potency | 1.3207 | 1 | 2 |
| cytochrome P450 2D6 | Homo sapiens (human) | Potency | 0.3890 | 1 | 1 |
| cytochrome P450 family 3 subfamily A polypeptide 4 | Homo sapiens (human) | Potency | 12.5176 | 1 | 2 |
| cytochrome P450, family 19, subfamily A, polypeptide 1, isoform CRA_a | Homo sapiens (human) | Potency | 10.7227 | 1 | 3 |
| DNA polymerase beta | Homo sapiens (human) | Potency | 25.1189 | 1 | 1 |
| DNA polymerase eta isoform 1 | Homo sapiens (human) | Potency | 53.1764 | 1 | 2 |
| DNA polymerase iota isoform a (long) | Homo sapiens (human) | Potency | 15.1846 | 1 | 3 |
| DNA polymerase kappa isoform 1 | Homo sapiens (human) | Potency | 17.3926 | 1 | 2 |
| estrogen nuclear receptor alpha | Homo sapiens (human) | Potency | 28.5011 | 8 | 26 |
| estrogen receptor 2 (ER beta) | Homo sapiens (human) | Potency | 41.1964 | 2 | 2 |
| estrogen-related nuclear receptor alpha | Homo sapiens (human) | Potency | 15.1862 | 6 | 21 |
| euchromatic histone-lysine N-methyltransferase 2 | Homo sapiens (human) | Potency | 53.4540 | 1 | 2 |
| farnesoid X nuclear receptor | Homo sapiens (human) | Potency | 15.1422 | 1 | 2 |
| flap endonuclease 1 | Homo sapiens (human) | Potency | 24.9937 | 1 | 3 |
| Fumarate hydratase | Homo sapiens (human) | Potency | 17.7828 | 1 | 1 |
| G | Vesicular stomatitis virus | Potency | 1.3207 | 1 | 2 |
| geminin | Homo sapiens (human) | Potency | 2.3109 | 1 | 1 |
| GLI family zinc finger 3 | Homo sapiens (human) | Potency | 2.3500 | 2 | 6 |
| glp-1 receptor, partial | Homo sapiens (human) | Potency | 14.3484 | 1 | 2 |
| GLS protein | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| glucocorticoid receptor [Homo sapiens] | Homo sapiens (human) | Potency | 13.8062 | 2 | 2 |
| Glutamate receptor 2 | Rattus norvegicus (Norway rat) | Potency | 26.3761 | 1 | 4 |
| Glycoprotein hormones alpha chain | Homo sapiens (human) | Potency | 0.5012 | 1 | 1 |
| Guanine nucleotide-binding protein G | Homo sapiens (human) | Potency | 10.0000 | 1 | 1 |
| heat shock 70kDa protein 5 (glucose-regulated protein, 78kDa) | Homo sapiens (human) | Potency | 28.1838 | 1 | 1 |
| heat shock protein beta-1 | Homo sapiens (human) | Potency | 58.2929 | 2 | 2 |
| Histamine H2 receptor | Cavia porcellus (domestic guinea pig) | Potency | 6.3096 | 1 | 3 |
| histone deacetylase 9 isoform 3 | Homo sapiens (human) | Potency | 9.4107 | 2 | 6 |
| Histone H2A.x | Cricetulus griseus (Chinese hamster) | Potency | 25.4754 | 2 | 8 |
| histone-lysine N-methyltransferase 2A isoform 2 precursor | Homo sapiens (human) | Potency | 19.9526 | 1 | 1 |
| HLA class I histocompatibility antigen, B alpha chain | Homo sapiens (human) | Potency | 1.3207 | 1 | 2 |
| huntingtin isoform 2 | Homo sapiens (human) | Potency | 12.5893 | 1 | 1 |
| hypothetical protein, conserved | Trypanosoma brucei | Potency | 27.7170 | 1 | 2 |
| hypoxia-inducible factor 1 alpha subunit | Homo sapiens (human) | Potency | 42.2707 | 2 | 3 |
| hypoxia-inducible factor 1, alpha subunit (basic helix-loop-helix transcription factor) | Homo sapiens (human) | Potency | 0.1995 | 2 | 2 |
| IDH1 | Homo sapiens (human) | Potency | 7.3078 | 1 | 1 |
| Inositol hexakisphosphate kinase 1 | Homo sapiens (human) | Potency | 1.3207 | 1 | 4 |
| Inositol monophosphatase 1 | Rattus norvegicus (Norway rat) | Potency | 1.9953 | 1 | 1 |
| Interferon beta | Homo sapiens (human) | Potency | 15.2677 | 3 | 6 |
| isocitrate dehydrogenase 1, partial | Homo sapiens (human) | Potency | 52.1194 | 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 | 15.5803 | 3 | 7 |
| luciferase | Photuris pensylvanica (Pennsylania firefly) | Potency | 10.0000 | 1 | 1 |
| luteinizing hormone receptor | Homo sapiens (human) | Potency | 84.9214 | 1 | 1 |
| Microtubule-associated protein tau | Homo sapiens (human) | Potency | 8.5539 | 2 | 2 |
| mitogen-activated protein kinase 1 | Homo sapiens (human) | Potency | 7.0795 | 1 | 1 |
| muscleblind-like protein 1 isoform 1 | Homo sapiens (human) | Potency | 2.8184 | 1 | 1 |
| neuropeptide S receptor isoform A | Homo sapiens (human) | Potency | 3.1824 | 3 | 3 |
| nuclear factor erythroid 2-related factor 2 isoform 1 | Homo sapiens (human) | Potency | 2.5756 | 2 | 4 |
| nuclear factor erythroid 2-related factor 2 isoform 2 | Homo sapiens (human) | Potency | 8.0965 | 1 | 2 |
| nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (p105), isoform CRA_a | Homo sapiens (human) | Potency | 39.7411 | 1 | 2 |
| nuclear receptor ROR-gamma isoform 1 | Mus musculus (house mouse) | Potency | 11.2202 | 1 | 1 |
| nuclear receptor subfamily 1, group I, member 3 | Homo sapiens (human) | Potency | 8.1261 | 3 | 9 |
| parathyroid hormone/parathyroid hormone-related peptide receptor precursor | Homo sapiens (human) | Potency | 66.0773 | 1 | 2 |
| peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 | Homo sapiens (human) | Potency | 48.0224 | 1 | 2 |
| peripheral myelin protein 22 | Rattus norvegicus (Norway rat) | Potency | 10.1815 | 1 | 1 |
| peroxisome proliferator activated receptor gamma | Homo sapiens (human) | Potency | 26.8450 | 2 | 2 |
| peroxisome proliferator-activated receptor delta | Homo sapiens (human) | Potency | 36.7195 | 1 | 1 |
| phosphoglycerate kinase | Trypanosoma brucei brucei TREU927 | Potency | 17.7828 | 1 | 1 |
| phosphopantetheinyl transferase | Bacillus subtilis | Potency | 79.0420 | 3 | 3 |
| plasminogen precursor | Mus musculus (house mouse) | Potency | 15.2113 | 1 | 2 |
| polyprotein | Zika virus | Potency | 17.7828 | 1 | 1 |
| PPM1D protein | Homo sapiens (human) | Potency | 18.5569 | 1 | 2 |
| pregnane X nuclear receptor | Homo sapiens (human) | Potency | 3.1248 | 2 | 3 |
| progesterone receptor | Homo sapiens (human) | Potency | 51.0406 | 1 | 2 |
| pyruvate kinase PKM isoform a | Homo sapiens (human) | Potency | 39.8107 | 2 | 2 |
| Rap guanine nucleotide exchange factor 3 | Homo sapiens (human) | Potency | 100.0000 | 1 | 1 |
| RAR-related orphan receptor gamma | Mus musculus (house mouse) | Potency | 8.9626 | 2 | 5 |
| retinoic acid nuclear receptor alpha variant 1 | Homo sapiens (human) | Potency | 22.3316 | 3 | 10 |
| retinoid X nuclear receptor alpha | Homo sapiens (human) | Potency | 29.0568 | 2 | 4 |
| serine-protein kinase ATM isoform a | Homo sapiens (human) | Potency | 13.0258 | 4 | 4 |
| serine/threonine-protein kinase PLK1 | Homo sapiens (human) | Potency | 0.8437 | 1 | 1 |
| SMAD family member 2 | Homo sapiens (human) | Potency | 6.7400 | 1 | 1 |
| SMAD family member 3 | Homo sapiens (human) | Potency | 6.7400 | 1 | 1 |
| Smad3 | Homo sapiens (human) | Potency | 10.0000 | 1 | 1 |
| Spike glycoprotein | Severe acute respiratory syndrome-related coronavirus | Potency | 39.8107 | 1 | 1 |
| survival motor neuron protein isoform d | Homo sapiens (human) | Potency | 18.4938 | 1 | 3 |
| T cell receptor, partial | Homo sapiens (human) | Potency | 6.2841 | 1 | 1 |
| TAR DNA-binding protein 43 | Homo sapiens (human) | Potency | 15.8489 | 1 | 1 |
| TDP1 protein | Homo sapiens (human) | Potency | 5.8312 | 2 | 8 |
| thioredoxin glutathione reductase | Schistosoma mansoni | Potency | 31.6228 | 1 | 1 |
| thyroid hormone receptor beta isoform 2 | Rattus norvegicus (Norway rat) | Potency | 21.6784 | 2 | 6 |
| thyroid hormone receptor beta isoform a | Homo sapiens (human) | Potency | 42.2395 | 2 | 2 |
| thyroid stimulating hormone receptor | Homo sapiens (human) | Potency | 13.5851 | 5 | 15 |
| transcriptional regulator ERG isoform 3 | Homo sapiens (human) | Potency | 31.6228 | 1 | 1 |
| TSHR protein | Homo sapiens (human) | Potency | 15.5035 | 2 | 2 |
| urokinase plasminogen activator surface receptor precursor | Mus musculus (house mouse) | Potency | 15.2113 | 1 | 2 |
| urokinase-type plasminogen activator precursor | Mus musculus (house mouse) | Potency | 15.2113 | 1 | 2 |
| USP1 protein, partial | Homo sapiens (human) | Potency | 42.8000 | 2 | 2 |
| v-jun sarcoma virus 17 oncogene homolog (avian) | Homo sapiens (human) | Potency | 8.1966 | 2 | 4 |
| 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 | 26.3761 | 1 | 4 |
| Vpr | Human immunodeficiency virus 1 | Potency | 39.8107 | 1 | 1 |
| WRN | Homo sapiens (human) | Potency | 50.1187 | 1 | 1 |