Clinical applications of flow cytometry.

By providing multiple analyses on single cells, flow cytometry allows the description of cellular heterogeneity, establishing the biologic counterpart of clinical heterogeneity common to most tumors. Analysis of DNA content, a reflection of cell ploidy, is useful in establishing the prognosis of many solid tumors, while analysis of other markers has been crucial in increasing our knowledge of lymphoid differentiation, classifying hematologic malignancies, and detecting minimal residual disease.