Merocyanine 540 staining of human leukemic cells: relation to stage of disease.

Previous work based on fluorescence microscopic observation has indicated that leukemic leukocytes and immature hematopoietic precursor cells show a greater permeability to the membrane stain, merocyanine 540 (MC) than normal, mature cells and that changes in MC permeability seem to be correlated with failure in membrane maturation during leukemic cell differentiation. In the interest of addressing questions concerning the efficacy of the MC staining reaction as a diagnostic tool in clinical contexts relevant to leukemia, we have looked for any correlations which might exist between the MC staining patterns displayed by circulating leukocytes, cellular morphology and the clinical status of 53 patients with leukemia and non-Hodgkin's lymphoma, using fluorescence activated cell sorting. In 85% of cases, MC staining was found to be correlated with blood status while in 15% of the cases discrepancies were found. These results are discussed in light of changes in the hematologic profiles of the patients during the clinical course.