Flow cytometric measurement of cellular ionized calcium concentration.

Abstract : Considerable interest has been directed at measuring intracellular ionized calcium concentration (Ca2+)i) in living cells. Calcium has an important role in a number of cellular functions, and perhaps most interestingly, can function to transmit information from the cell membrane to regulate diverse cellular functions. Until the early 1980s it was not possible to measure (Ca2+)i in small intact cells, and attempts to measure cytosolic calcium were restricted mostly to large invertebrate cells where the use of microelectrodes was possible. A new family of fluorescent dyes was developed by Tsien et al. (80), and with quin2, it was possible for the first time to measure (Ca2+)i in virtually any population of cells. In 1985, a second family of dyes was developed with the invention of fura-2 and indo-1 (23), and it became possible to measure (Ca2+)i in intact single cells of nearly all types. The purpose of this review is to discuss the measurement of (Ca2+)i using flow cytometry to analyze cells loaded with the fluorescent to date. Keywords: Lymphocytes, T lymphocytes, Reprints.