Figure 1: Constitutive phosphorylation of Ret in TT cells lysed in the presence of phosphatase inhibitors* (phospho lysate) is detected by PathScan<sup>®</sup> Phospho-Ret (panTyr) Sandwich ELISA Kit #7034 (upper, right). In contrast, a low level of phospho-Ret protein is detected in TT cells lysed in the absence of phosphatase inhibitors* (nonphospho lysate). Similar levels of total Ret protein from both nonphospho or phospho lysates are detected by PathScan<sup>®</sup> Total Ret Sandwich ELISA Kit #7032 (upper, left). Absorbance at 450 nm is shown in the top figure while corresponding western blots using a Phospho-Ret (Tyr905) Rabbit Antibody #3221 (right) or a total Ret (C31B4) Rabbit mAb #3223 (left) are shown in the bottom figure. *Phosphatase inhibitors include sodium pyrophosphate, β-glycerophosphate and Na<sub>3</sub>VO<sub>4</sub>.