Laboratory techniques Assessment ofDNA content and cell cycle distribution of erythroid and myeloid cells from bone marrow

A method is described for the measurement ofDNA index and cell cycle distribution in purified erythroid and myeloid populations from human bone marrow. Erythroid cells were prepared after complement mediated lysis of non-erythroid marrow cells. Myeloid cells were obtained by fluorescence activated cell sorting by forward and wide angle light scatter. Mononuclear marrow cells were prepared with a density gradient. Nuclei prepared from the separated populations were stained with propidium iodide. Myeloid cells had a higher DNA index than erythroid cells, and the mononuclear preparation had an intermediate value. There were more erythroid than myeloid cells in the S and G2M phases of the cell cycle. These lineage differences are particularly relevant when considering data derived from unseparated bone marrow cells, and further experiments are needed to determine the origin of these anomalies.