Emerging applications of flow cytometry in solid tumor biology.

Despite considerable interest during the early clinical development of flow cytometry, its application to solid tumours has been largely ignored in recent years. However, with rapid progress in cancer biology and molecular therapeutics, linked to technical developments in the areas of flow cytometry instrumentation, reagents, and data analysis, it is timely to re-evaluate this role. This article places emphasis on the unique potential of flow cytometry to analyze heterogeneous cell populations, and to provide information on the functional status of regulatory processes by the simultaneous measurement of multiple key elements. Major obstacles to progress addressed include the acquisition of adequate clinical samples, tissue disaggregation to produce single cells suspensions suitable for flow cytometry, and protocols to label intracellular as well as cell surface antigens.