Bromocresol Purple

CAS Number:  115-40-2
Molecular Weight: 540.22
MDL number: MFCD00011681
EC Index Number: 204-087-8


  • Bromocresol Purple has been used for staining of Saccharomyces cerevisiae.[1]
  • Spectrophotometric determination of serum-albumin

Biochem/physiol Actions

Bromocresol purple is a pH indicator which changes color from yellow (at low pH 5.2) to violet (above pH 6.8).[2] It is mainly used as a fluorescent stain in yeast cells. It helps in dead cell count for cells with plasma membrane damage. Cells with proper cell membrane are not stained, while damaged cells are seen as blue-grey ghosts.[3]

product line BioReagent
Quality Level 200
Assay ≥89.0% (HPLC)
λmax 549 nm
form powder
composition Dye content, 90%
technique(s) titration: suitable
pH 5.2-6.8, yellow to purple
visual transition interval 5.2-6.8, yellow to blue
mp 240 °C (dec.) (lit.)
solubility ethanol: 1 mg/mL
λmax 419 nm
ε (extinction coefficient) ≥22000 at 418-424 nm in methanol
suitability suitable for indicator
application(s) diagnostic assay manufacturing



storage temp. room temp
SMILES string Cc1cc(cc(Br)c1O)C2(OS(=O)(=O)c3ccccc23)c4cc(C)c(O)c(Br)c4
InChI 1S/C21H16Br2O5S/c1-11-7-13(9-16(22)19(11)24)21(14-8-12(2)20(25)17(23)10-14)15-5-3-4-6-18(15)29(26,27)28-21/h3-10,24-25H,1-2H3