Figure 1. Constitutive phosphorylation of Bcr-Abl and c-Abl in K-562 cells lysed in the presence of phosphatase inhibitors* (phospho lysate) is detected by PathScan ® Phospho-c-Abl (Tyr412) Sandwich ELISA Kit #12070. In contrast, a low level of phospho-Bcr-Abl and phospho-c-Abl protein is detected in K-562 cells lysed in the absence of phosphatase inhibitors* (nonphospho lysate). Absorbance at 450 nm is shown in the top figure while corresponding western blots using c-Abl Antibody #2862 (left panel) and Phospho-c-Abl (Tyr412) (247C7) Rabbit mAb #2865 (right panel) are shown in the bottom figure. *Phosphatase inhibitors include sodium pyrophosphate, β-glycerophosphate, and Na 3 VO 4 .
Figure 2. The relationship between protein concentration of phospho or nonphospho lysates and the absorbance at 450 nm is shown. Unstarved K-562 cells were cultured (10 6 cells/ml) and lysed with or without addition of phosphatase inhibitors to the lysis buffer (phospho or nonphospho lysate, respectively).