Fura-2-acetoxymethyl ester

Fura-2-acetoxymethyl ester, often abbreviated Fura-2AM, is a membrane-permeant derivative of the ratiometric calcium indicator Fura-2 used in biochemistry to measure cellular calcium concentrations by fluorescence.[1] When added to cells, Fura-2AM crosses cell membranes and once inside the cell, the acetoxymethyl groups are removed by cellular esterases. Removal of the acetoxymethyl esters regenerates "Fura-2", the pentacarboxylate calcium indicator. Measurement of Ca2+-induced fluorescence at both 340 nm and 380 nm allows for calculation of calcium concentrations based 340/380 ratios. The use of the ratio automatically cancels out certain variables such as local differences in fura-2 concentration or cell thickness that would otherwise lead to artifacts when attempting to image calcium concentrations in cells.

Fura-2-acetoxymethyl ester
Fura 2AM.png
IUPAC name
Acetoxymethyl 2-[5-[bis[(acetoxymethoxy-oxo-

methyl)methyl]amino]-4-[2-[2-[bis[(acetoxymethoxy-oxo- methyl)methyl]amino]-5-methyl-phenoxy]ethoxy]benzofuran-

Other names
3D model (JSmol)
Molar mass 1001.85
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references


  1. ^ Oakes, S. G; Martin Wj, 2nd; Lisek, C. A; Powis, G (1988). "Incomplete hydrolysis of the calcium indicator precursor fura-2 pentaacetoxymethyl ester (fura-2 AM) by cells". Analytical Biochemistry. 169 (1): 159–66. doi:10.1016/0003-2697(88)90267-9. PMID 3369679.