[Megakaryocyte ploidy in patients with myelodysplastic syndrome--by microcytofluorometry with DAPI staining after...

In the myelodysplastic syndrome (MDS) patients the ploidy distribution of megakaryocyte DNA was rarely reported. We applied DAPI (4',6-diamidino-2-phenylindole) staining for measuring nuclear DNA content in megakaryocytes which have been morphologically identified on the Wright-Giemsa stained smear in 8 normal subjects and 12 MDS patients. Briefly, megakaryocytes morphologically examined on a Wright-Giemsa stained smear were photographed, and were located. We then removed the Wright-Giemsa stains by immersing it in 50% ethanol, 37 degrees C for 1 hour and 100% methanol, 37 degrees C for 1 hour. The DAPI staining was performed in DAPI solution (DAPI 0.01 mg/ml, pH 7.4 Tris-EDTA-2 Na buffer solution and 0.01 mol 2-mercaptoethylamine hydrochloride were mixed at the ratio of 0.5: 98.5: 1.0) for more than 30 min. The amount of nuclear DNA in the megakaryocyte previously identified was measured by cytofluorometry. The population of megakaryocyte in the normal subjects was the largest in the 16N, and in the 10 cases of the 12 MDS patients was the largest in the 8N, in the other 2 cases was the largest in the 4N. These results represent the development of the megakaryocyte nucleus in the MDS patients may be disturbed.