Rhod-2 AM (1 mg), AdipoGen Life Sciences. Chemical. CAS: 145037-81-6. Formula: C52H59BrN4O19. MW: 1123.96. Synthetic. Long-wavelength cell-permeant Ca2+ indicator. Rhod-2/AM is an acetoxymethyl ester derivative of Rhod 2 that can be easily loaded into cells via incubation and used for quantifying intracellular Ca2+ concentration allowing non-invasive measurement of calcium ions in live cells. This fluorogenic probe for intracellular Ca2+ operates in the visible spectrum. Rhod-2/AM itself does not bind Ca2+, but it is readily hydrolyzed to Rhod-2 by endogenous esterases once the dye enters cells. Rhod-2 has the longest fluorescent emission signal of the commonly used calcium indicators. Its signal intensity is the strongest of all the calcium probes. Spectral Data: λex 550nm, λem 578nm in methanol; λex 549nm, λem 578nm in DMSO; λex 550nm, λem 570nm in Chloroform:Methanol (90:10).