苏科商城

其他名称：溴酚兰；四溴酚磺酞；四溴酚磺酚酞；四溴苯酚磺酞；四溴苯酚磺酰酞；3,3',5,5'-四溴磺酚酞

C19H10Br4O5S=669.97

pH变色域：3.0（黄）～4.6（蓝紫）

质量吸收系数ε/（L/cm•g）：≥115.0

性状：浅黄色到棕黄色粉末。易溶于氢氧化钠溶液，溶于甲醇、乙醇和苯，微溶于水(约0.4G/100ml)。熔点279℃(分解)，最大吸收波长422nm

保存：RT

Bromophenol blue (3′,3″,5′,5″-tetrabromophenolsulfonphthalein, BPB, albutest) is used as a pH indicator, a color marker, and a dye. It can be prepared by slowly adding excess bromine to a hot solution of phenolsulfonphthalein in glacial acetic acid.

As an acid–base indicator, its useful range lies between pH 3.0 and 4.6. It changes from yellow at pH 3.0 to blue at pH 4.6; this reaction is reversible. Bromophenol blue is structurally related to phenolphthalein (a popular indicator).

Bromophenol blue is also used as a color marker to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Since bromophenol blue carries a slight negative charge at moderate pH, it will migrate in the same direction as DNA or protein in a gel;

Bromophenol blue is also used as a dye. At neutral pH, the dye absorbs red light most strongly and transmits blue light. Solutions of the dye, therefore, are blue. At low pH, the dye absorbs ultraviolet and blue light most strongly and appears yellow in solution. In solution at pH 3.6 (in the middle of the transition range of this pH indicator) obtained by dissolution in water without any pH adjustment, bromophenol blue has a characteristic green red color, where the apparent color shifts depending on the concentration and/or path length through which the solution is observed.