Bromocresol green

tan to yellow crystals

Bromocresol Green (BCG) is a pH sensitive triphenylmethane dye useful in a variety of colorimetric detection technologies. BCG is used as a tracking dye for DNA agarose gel electrophoresis, in protein determinations and in charge-transfer complexation processes. In TLC BCG is used for visualisation of the compounds with functional groups whose pKa is below 5.0.

Bromocresol Green is a pH sensitive indicator used in the growth medium for microorganisms and titrations. It is useful in various colorimetric detection studies and as an actively tracking dye for DNA agarose gel electrophoresis. It acts as an inhibitor of prostaglandin E2 transport protein. It is also used in TLC for visualizing compounds containing functional groups having pKa less than 5.

As indicator, pH 3.8 yellow; pH 5.4 blue-green.

ChEBI: Bromocresolgreen is a member of benzofurans.

Moderately toxic.

Crystallise the dye from glacial acetic acid or dissolve it in aqueous 5% NaHCO3 solution and precipitate it from the hot solution by dropwise addition of aqueous HCl. Repeat this until the UV/VIS-extinction did not increase 423nm. It is an indicator: at pH 3.81 at max (yellow) and pH 5.4 (blue-green). [Beilstein 19/3 V 460.]