Treatment of Mks with QITP serum plus drug does not affect endomitosis. Cultured CD34⁺ cells were treated on day 4 with QITP serum + Qn or with controls (QITP serum − QN or NS + Qn) and analyzed after 5 or 6 days in culture. (A) Mks stained with anti-GPIIb antibody and PI in hypotonic citrate buffer. The DNA content of the GPIIb⁺ population was analyzed by flow cytometry. No differences were observed among the groups analyzed. (B) Mks stained with anti-GPIX antibody conjugated to Alexa Fluor 488 and imaged by confocal microscopy. Cells were chosen randomly (n = 94) and their area calculated using ImageJ software. The graph shows the mean ± SD. No significant differences were observed. (C) Cultured Mks centrifuged onto slides, stained for morphology with Wright/Giemsa staining, and imaged with a Zeiss Axioskop microscope and AxioVision 3.1 software (10× objective using an Axiocam camera; Zeiss). Scale bar indicates 50 μm. (D) Mks at different stages of development (20× objective). Bar indicates 20 μm. Images were cropped and revised using Adobe Photoshop CS5. (E) Percentage of monolobed, bilobed, or multilobed Mks calculated by randomly selecting 750 cells from each treatment group. The graph shows the percentage ± SD.