Fig. 5.
Kinetic changes of PTP activities in cytosolic (A) and membrane (B) fractions and erythroid colony number (C) from normal (•) and PV (○) ECFC. Cells were collected at the indicated periods of suspension culture. Preparation of cytosolic and membrane extracts and assays of colony formation were performed as described in Materials and Methods. Cell extracts containing 2.0 μg total proteins were used to measure PTP activity with 32P-labeled ENDYINASL, and 1,000 cells were analyzed for colony formation in plasma clot cultures.