Bromophenol Blue is a pH indicator, and a dye appearing as a strong blue color. ... Bromophenol blue has a slight negative charge and will migrate the same direction as DNA, allowing the user to monitor the progress of molecules moving through the gel. The rate of migration varies with gel composition.

How does bromophenol blue bind proteins?

Bromophenol blue (BPB), a phenolphthalein anionic dye, binds to proteins under neutral to acidic conditions. ... Usually, urinary protein levels are determined using a dipstick assay. However, this method is affected by urine volume and color, which can lead to inaccurate results (1-3).

Why is bromophenol blue used as an indicator?

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.