Human leukemia cell line K562 cell lines are stained with Wright-Giemsa staining solutions. K562 cells are prepared on slide glass by cytocentrifugation, fixed in ice-cold methanol, and stained with Wright solution (Sigma) followed by staining with Giemsa solution (Sigma). This is also usd for megakaryocyte differentiation. Wright-Giemsa solution can be purchased from Muto Pure Chemical Co., Tokyo, Japan