Fig. 3.
Determination of culture days for the megakaryocyte colony collection. Peripheral blood CD34+ cells (4.5 × 103 cells/mL) were cultured with 10 ng/mL TPO and 10 ng/mL SCF in 35-mm plastic dishes for 14 days. Megakaryocyte colonies that contained megakaryocytes with proplatelet formation were counted daily on days 1 through 14 of the culture period, using an inverted microscope. Their number peaked between days 9 and 10. Therefore, collection of the megakaryocyte colonies from the culture dishes was determined on the 9th day of culture, before maximal proplatelet production. The data are the means ± SEM from duplicate cultures of one experiment.