Bromophenol blue is a dye that belongs to the triphenylmethane family and serves as a pH indicator, electrophoretic color marker, and a dye. It can be synthesized by adding bromine to a hot solution of phenolsulfonphthalein in glacial acetic acid. As a pH indicator, it changes from yellow at pH 3.0 to blue at pH 4.6. Structurally parallel to phenolphthalein, bromophenol blue also acts as a dye, absorbing red light at neutral pH and transitioning colors based on pH levels and concentration. Its dichromaticity index is the highest known, meaning it exhibits significant color changes with varying sample thickness.
CAS No.: 115-39-9
Synonyms: Albutest; Tetrabromphenol Blue; 3,3′,5,5′-Tetrabromophenolsulfonphthalein; 3′,3”,5′,5”-Tetrabromophenolsulfonephthalein; CCRIS 5487; Bromphenol Blue Sultone Form
| Physical Properties | |
| Chemical formula | C19H10Br4O5S |
| IUPAC Name | 2,6-dibromo-4-[3-(3,5-dibromo-4-hydroxyphenyl)-1,1-dioxo-2,1λ6-benzoxathiol-3-yl]phenol |
| Molecular weight | 670.0 g/mol |
| Solubility | Soluble in Water, Methyl, Ethanol, Benzene, DMSO, and dimethyl formamide |
| Flash point | <200 °F |
| Density | 2.2 g/mL |
| pKa | 7.0 |
| Chemical Properties | |
| Colour | Dark Bluish-Black |
| State | Crystalline Solid Powder |
| Melting point | 270°C |
| λmax | 590 nm |
| pKa | 4.0 |
| Pictograms : |   |
| Hazard Statements : | H225: Highly flammable liquid and vapour |
| Precautionary statements : | P303+P361+P353: IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water [or shower]. P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present, and easy to do. Continue rinsing. P501: Dispose off contents/container following local/regional/national/international regulations. |
Bromophenol blue is a dye that belongs to the triphenylmethane family and serves as a pH indicator, electrophoretic color marker, and a dye. It can be synthesized by adding bromine to a hot solution of phenolsulfonphthalein in glacial acetic acid. As a pH indicator, it changes from yellow at pH 3.0 to blue at pH 4.6. Structurally parallel to phenolphthalein, bromophenol blue also acts as a dye, absorbing red light at neutral pH and transitioning colors based on pH levels and concentration. Its dichromaticity index is the highest known, meaning it exhibits significant color changes with varying sample thickness.
CAS No.: 115-39-9
Synonyms: Albutest; Tetrabromphenol Blue; 3,3′,5,5′-Tetrabromophenolsulfonphthalein; 3′,3”,5′,5”-Tetrabromophenolsulfonephthalein; CCRIS 5487; Bromphenol Blue Sultone Form
| Physical Properties | |
| Chemical formula | C19H10Br4O5S |
| IUPAC Name | 2,6-dibromo-4-[3-(3,5-dibromo-4-hydroxyphenyl)-1,1-dioxo-2,1λ6-benzoxathiol-3-yl]phenol |
| Molecular weight | 670.0 g/mol |
| Solubility | Soluble in Water, Methyl, Ethanol, Benzene, DMSO, and dimethyl formamide |
| Flash point | <200 °F |
| Density | 2.2 g/mL |
| pKa | 7.0 |
| Chemical Properties | |
| Colour | Dark Bluish-Black |
| State | Crystalline Solid Powder |
| Melting point | 270°C |
| λmax | 590 nm |
| pKa | 4.0 |
| Pictograms : | |
| Hazard Statements : | H225: Highly flammable liquid and vapour |
| Precautionary statements : | P303+P361+P353: IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water [or shower]. P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present, and easy to do. Continue rinsing. P501: Dispose off contents/container following local/regional/national/international regulations. |
Bromophenol blue is added to DNA samples as a tracking dye during gel electrophoresis.
Bromophenol blue is a good indicator because it has a clear color change over a specific pH range (yellow at acidic pH and blue at basic pH), making it useful for monitoring pH changes in various chemical and biological processes.
Bromophenol blue staining binds to proteins and nucleic acids, tracking their migration during electrophoresis by changing color with pH.
Bromophenol blue is negatively charged at neutral pH.
Bromophenol blue binds to proteins, allowing them to be visualized during electrophoresis. It also helps track the progress of protein migration in the gel.
