Spectrum carries Cresol Red, also known as o-Cresolsulfonphthalein, among its high quality inventory. Cresol red is commonly used with lead acetate for the detection of urease after PAGE. It is also used as an indicator with the following transition intervals: pH 1.8 (orange) to pH 2.0 (yellow); pH 7.0 (yellow) to pH 8.8 (violet).