ABSTRACT
To observe the K562 cell line derived from a patient of chronic myelogenous leukemia differentiated into megakaryocytes by growing in the presence of phorbol myristate acetate [PMA]. The differentiation process of K562 cells was monitored by the expression of a platelet cell marker, CD61 through immunocytochemistry using mouse alkaline phosphatase antialkaline phosphatase [APAAP] complex employing fast red TR as substrate, crystal violet and MTT assay used for cell growth analysis. The crystal in the presence of PMA, cells obtained were of large size and less in number as compared to cells incubated without PMA where they were of smaller size and more in number and immunochemical reaction used to detect the presence of CD61, a platelet cell marker that is expressed during differentiation of K562 cells to megakaryocytes. The results showed that the addition of PMA to the growing culture of K562 cell lines induced differentiation, observed through CD61 expression and increase in cell size and cessation of proliferation