Separation of diploid from aneuploid cells in acute lymphoblastic leukaemia

A new method for the separation of diploid and aneuploid cells from blood of patients with leukaemia is described. Density gradient separation using a modified silica particle gradient was combined with analysis of cellular DNA content by flow cytometry. Submicroscopic levels of diploid or aneuploid cells were enriched up to 90% purity. Three patients with acute lymphoblastic leukaemia and no evidence of aneuploid cells after separation are in continuing complete remission after 24.5-47 months. Two patients with aneuploid cells detected after separation expired in relapse 0.5 and 3 months later. Cell separation prior to flow cytometric analysis might be a useful tool to detect submicroscopic levels of aneuploid leukaemic cells in blood and bone marrow, and to predict impending relapse.