Cytosolic Ca2+ plays an important role in cellular biology, and since its identification as a second messenger, a number of techniques and methods to analyze the changes in cytosolic Ca2+ concentration ([Ca2+]c) induced by physiological agonists have been developed. Changes in [Ca2+]c might be determined in single cells or in cell populations. Measurement in single cells allows to determine changes in [Ca2+]c at a subcellular level but often results in heterogeneous responses among cells. Determination of intracellular Ca2+ mobilization at the cell population level reduces this heterogeneity and allows [Ca2+]c measurements in small cells that load little amounts of indicator. Here, we describe the measurement of agonist-evoked changes in [Ca2+]c associated with Ca2+ influx in cell populations.
Keywords: Calcium homeostasis; Cytosolic calcium; ELISA; Flow cytometry; Fluorescence spectrophotometer; Fluorescent probes; Ion channels.