Analysis of free intracellular calcium by flow cytometry: Multiparameter and pharmacologic applications

Flow cytometry offers numerous advantages over traditional techniques for measuring intracellular Ca2+ in lymphoid and nonlymphoid cells. In particular, the heterogeneity of cell responses can be defined by flow cytometry, and multiparameter analyses permit the determination of intracellular Ca2+ in surface-marker-defined target cells as well as correlation of changes in Ca2+ with other biochemical markers, including ligand binding. This article presents several established methods for measuring intracellular Ca2+ by flow cytometry in lymphoid and nonlymphoid cells. Examples are provided for determination of Ca2+ in human peripheral blood leukocytes and two human epithelial cell lines grown in monolayer. In addition, applications are reviewed or presented for correlating changes In intracellular Ca2+ with other cell parameters, including cell cycle analysis, changes in cell membrane integrity, and the induction of apoptosis markers. Finally, a number of novel sample handling capabilities useful for performing kinetic analyses of Ca2+ changes by flow cytometry are now available and one application is presented which is finding utility in pharmacologic studies, (C) 2000 Academic Press.