Spectrum Chemical offers Bromocresol Purple sodium salt among its high quality inventory. Also known as 5',5''-Dibromo-o-cresolsulfonphthalein, it is a water soluble dye used as an protein probe. It has been used in the spectrophotometric determination of serum-albumin. It is also a pH indicator with a transition interval from 5.2 - 6.8 (yellow to purple).