Thermo Scientific Pierce Phosphatase Inhibitors preserve protein phosphorylation from phosphatases in cell and tissue extracts. Relative levels of total and phosphorylated protein were determined following protein extraction in the absence (–) or presence (+) of phosphatase inhibitors for (A) AKT and PDGFR in serum-starved, PDGF-stimulated (100 ng/mL) NIH 3T3 cell extracts and (B) ERK1/2 in liver and spleen tissue extracts. C: The degree of inhibition for protein, acid and alkaline phosphatase activity was determined in mouse brain extract following treatment with Pierce Phosphatase Inhibitor Tablets or another commercially available phosphatase inhibitor tablet.