Cresol Red

Cresol Red
Identifiers
CAS number	1733-12-6
PubChem	73013
ChemSpider	65818 Y
Jmol-3D images	Image 1 Image 2
SMILES Cc1cc(ccc1O)/C(=C/2C=CC(=O)C(=C2)C)c3ccccc3OS(O)=O O=S2(=O)OC(c1ccccc12)(c3ccc(O)c(c3)C)c4ccc(O)c(c4)C
InChI 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 Y Key: OBRMNDMBJQTZHV-UHFFFAOYSA-N Y InChI=1/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 Key: OBRMNDMBJQTZHV-UHFFFAOYAD
Properties
Molecular formula	C21H17NaO5S
Molar mass	404.41 g/mol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cresol Red (full name: o-Cresolsulfonephthalein) is a triarylmethane dye frequently used for monitoring the pH in aquaria.

pH indicator

Cresol Red (pH indicator)
below pH 7.2		above pH 8.8
7.2	↔	8.8

Molecular biology

Cresol Red can be used in many common molecular biology reactions in place of other loading dyes. Cresol Red does not inhibit Taq polymerase to the same degree as other common loading dyes.

Color marker

Cresol Red can also be used as a color marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. In a 1% agarose gel it runs approximately at the size of a 125 base pair (bp) DNA molecule (it depends on the concentration of buffer and other component). Bromophenol blue and xylene cyanol can also be used for this purpose.

References

External links

• Cresol Red at OpenWetWare life scientists' wiki