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|Section2= |Section3= }} Bromocresol green (BCG) is a dye of the triphenylmethane family (triarylmethane dyes). It is used as a pH indicator in applications such as growth mediums for microorganisms and titrations. ==Properties== In aqueous solution, Bromocresol green will ionize to give the monoanionic form (yellow), that further deprotonates at higher pH to give the dianionic form (blue),〔(【引用サイトリンク】title=Acid-Base Indicators )〕 which is stabilized by resonance: :450px The Dissociation constant (pKa) of this reaction is 4.8. The acid and basic forms of this dye have an isosbestic point in their spectra, around 515 nm. An ethanol solution (0.04 wt.%) of bromocresol green has been proposed for TLC staining and is suitable for visualisation of the compounds with functional groups whose pKa is below 5.0 (carboxylic acids, sulfonic acids, etc.). These appear as yellow spots on a light or dark blue background; no heating is necessary. Bromophenol blue solution can be used for the same purpose. The compound is synthesized by bromination of cresol purple (''m''-cresolsulfonphthalein). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「bromocresol green」の詳細全文を読む スポンサード リンク
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