THUNDER™ Phosphatase Inhibitor Cocktail (100X) is specially formulated for use with Phospho and Total THUNDER™ TR-FRET Cell Signaling Assay Kits. This cocktail is already provided in these kits, but can be ordered separately. The Phosphatase Inhibitor Cocktail is used to prevent dephosphorylation of phosphorylated proteins from active serine/threonine and tyrosine phosphatases present in whole cell extract.