Measurement of Free Cytosolic Calcium Concentration ([Ca2+]i) in Single CHO-K1 Cells

Abstract

This is a protocol to analyze the functional response of single CHO-K1 cells to a given treatment in terms of changes in free cytosolic calcium concentration ([Ca2+]i). This is possible by using the Ca2+ indicator dye Fura-2 AM, a polyamino carboxylic acid that binds to free intracellular calcium and is excited at 340 nm and 380 nm. The ratio of the emissions at 505 nm after excitation with those wavelengths is directly correlated to the amount of intracellular calcium. This protocol can be applied to other cell types (cell lines or primary cell cultures) by changing the culture conditions accordingly to the cell type.