RT-PCR analysis of BaF3/mMpl and MK RNA after stimulation with TPO or IFN-α.

BaF3/mMpl (A) or purified MK (B) were starved for 14 or 7 hours, respectively, and either untreated or stimulated with 10 ng/mL mTPO for 10 minutes, 500 U/mL IFN-α for 4 hours, or both. After RNA harvest, RT-PCR was conducted with SOCS-1–specific oligo-deoxynucleotide primers for 30 (A) or 24 (B) cycles, and the products were analyzed by ethidium bromide staining of agarose gels. Amplification of both c-Mpl and GAPDH served as controls. Similar experiments were performed twice with BaF3/mMpl cells and 3 times with MK.