An activation-specific STAT5 antibody recognizes tyrosine-phosphorylated STAT5.

Ba/F3–EPO-R, DA-3–EPO-R, and HCD-57 cells were incubated for 4 hours in the absence of cytokine and then stimulated with various cytokines as shown; 100 μg protein lysate was resolved via SDS-PAGE and transferred to nitrocellulose. The membrane was incubated with an activation-specific STAT5 antibody (1 μg/mL) followed by HRP–protein A (1:5000) (top). Immunoreactive proteins were detected by enhanced chemiluminescence. The membrane was stripped and reprobed with an antibody that recognizes total STAT5 (1:5000) (bottom). pSTAT5 indicates phosphorylated STAT5; Ab, antibody.