PHENOL RED SODIUM SALT ACS GRADE excellent quality manufacturer , exporter and supplier. Phenol Red has been used for preparation of phosphate buffer saline (PBS)-with phenol red for microfluidic assay for simultaneous culture of multiple cell types. It has also been used for horseradish peroxidase-phenol red (HRP-PR) H2O2 (hydrogen peroxide) detection assay to identify redox cycling compounds. Phenol Red is a pH indicator which changes color from yellow to red.