Effect of JTZ-132 on mouse CFU-Meg. Mouse bone marrow cells (7.5 × 105 cells/chamber) were cultured with 100 ng/mL rhTPO or 1, 3, and 10 μmol/L JTZ-132 in collagen gel of double-chamber slides at 37°C for 7 days. Collagen gels were dehydrated, fixed, and stained with acetylthiocholiniodide at room temperature for 3.5 hours. The numbers of colonies (orange-brown) were counted with use of a stereoscopic microscope. CFU-Meg was defined as containing at least 3 megakaryocytes per colony. Data represent mean ± SEM of the results from 3 mice.