Problems with the application of quin‐2‐AM to measuring cytoplasmic free calcium in plant cells

Abstract

Abstract Attempts have been made to use the fluorescent calcium quin‐2 to measure cytoplasmic free calcium in a variety of plant cells. Failure to measure intracellular fluorescence can be attributed to extracellular hydrolysis of the membrane‐permeable ester quin‐2‐AM used to load the cells. Attempts to overcome this problem by long incubation times showed that the by‐product of ester hydrolysis, formaldehyde, is inhibitory to cell growth. Thus, it seems that the applicability of the acetoxymethyl ester of quin‐2 for cytoplasmic calcium measurements in plant cells is limited, though quin‐2 could still be very useful in some cells, especially if more suitable esters or micro‐injection are used.