114472

Cresol red

indicator grade, Dye content 95 %

• Synonym(s): o-Cresolsulfonphthalein
• Empirical Formula (Hill Notation): C₂₁H₁₈O₅S
• CAS Number: 1733-12-6
• Molecular Weight: 382.43
• Beilstein: 343399
• EC Number: 217-064-2
• MDL number: MFCD00005878
• UNSPSC Code: 12171500
• PubChem Substance ID: 24847173
• NACRES: NA.47

Properties

• grade: indicator grade
• Quality Level: 200
• form: powder or crystals
• composition: Dye content, 95%
• technique(s): titration: suitable
• color: red-brown
• pH: 7.2-8.8, yellow to red
• useful pH range: 1.8-2.0, orange to yellow(acid); 7.0-8.8, yellow to violet(alkaline)
• mp: 290 °C
• density: 0.998 g/cm³
• λmax: 367 nm (2nd); 570 nm
• application(s): diagnostic assay manufacturing; hematology; histology
• storage temp.: room temp
• SMILES string: Cc1cc(ccc1O)C2(OS(=O)(=O)c3ccccc23)c4ccc(O)c(C)c4
• InChI: 1S/C21H18O5S/c1-13-11-15(7-9-18(13)22)21(16-8-10-19(23)14(2)12-16)17-5-3-4-6-20(17)27(24,25)26-21/h3-12,22-23H,1-2H3
• InChI key: OBRMNDMBJQTZHV-UHFFFAOYSA-N

Description

General description

Cresol Red, also known as o-cresol red, belongs to the phthalein and sulphonphthalein group of dyes. Cresol red changes color from orange to yellow at pH between 0.2-1.8 and yellow to violet at pH between 7.0-8.8. In alkaline solutions, cresol red is present as a hydrophilic dianion. The dianion is small and is violet in color, possessing a larger conjugated system than the yellow hydroxyquinone.

Application

Cresol Red is a widely used pH indicator for routine pH assessments like microbial culture media preparations. In addition, Cresol red is a suitable constituent of PCR reagent systems. Cresol Red is used as a tracking dye in DNA, RNA (agarose), and protein (polyacrylamide) electrophoresis.

Safety Information

• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves