Skip to Content
Merck
CN

114472

Sigma-Aldrich

Cresol red

indicator grade, Dye content 95 %

Synonym(s):

o-Cresolsulfonphthalein

Sign Into View Organizational & Contract Pricing

Select a Size

About This Item

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

Key Documents

View All Documentation
Technical Service
Need help? Our team of experienced scientists is here for you.
Let Us Assist
Technical Service
Need help? Our team of experienced scientists is here for you.
Let Us Assist

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

Looking for similar products? Visit Product Comparison Guide

Related Categories

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.

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Choose from one of the most recent versions:

Certificates of Analysis (COA)

Lot/Batch Number
BCCN5450
BCCL9070
BCCJ9752
BCCH4332
BCCG0571

Don't see the Right Version?

If you require a particular version, you can look up a specific certificate by the Lot or Batch number.

Search for a COA

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

Atsushi Seki et al.
Analytica chimica acta, 582(1), 154-157 (2007-03-28)
Novel spectroscopic sensor based on a hetero-core structured fiber optic is described in this paper. The hetero-core structured fiber optic consists of multi mode fibers and a short piece of single mode fiber which was inserted in the multi mode
Paula C A Jerónimo et al.
The Analyst, 130(8), 1190-1197 (2005-07-16)
An optical biosensor based on immobilised carbonic anhydrase and its application to the determination of the anti-glaucoma agent acetazolamide by enzyme inhibition measurements, is described. The enzyme and a pH indicator dye, cresol red, were physically immobilised in overlapped sol-gel
R Schubert
Zentralblatt fur Bakteriologie, Mikrobiologie und Hygiene. Serie B, Umwelthygiene, Krankenhaushygiene, Arbeitshygiene, praventive Medizin, 187(3), 266-268 (1989-02-01)
A new medium is described for the isolation of P. aeruginosa organisms which have been damaged by chlorination. This medium utilises the fact that with arginine. P. aeruginosa produces a strongly alkaline reaction resulting in an easily identified colour change
H S Van Walraven et al.
European journal of biochemistry, 144(3), 555-561 (1984-11-02)
ATP hydrolysis-induced proton translocation and electric potential generation have been studied in ATPase proteoliposomes by means of various optical probes. The proteoliposomes consisted of reconstituted ATPase complex and native lipid mixture isolated from the thermophilic cyanobacterium Synechococcus 6716 [Van Walraven
Maurizio Caselli et al.
Annali di chimica, 92(5-6), 501-512 (2002-07-20)
The pKa of 3',3",5',5"tetrabromo-m-cresolsulfonephtalein (Bromocresol Green) and o-cresolsulphonephtalein (Cresol Red) was spectrophotometrically measured in a water/AOT/isooctane microemulsion in the presence of a series of buffers carrying different charges at different water/surfactant ratios. Extended Principal Component Analysis was used for a
View All Related Papers

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service