Indo-1 acetomethoxy (AM) is a popular UV-excitable calcium indicator, similar to Fura-2. In contrast to Fura-2, Indo-1 has a dual emission peak. The main emission peak in calcium-free solution is 475nm while in the presence of calcium the emission is shifted to 400nm. Indo-1 AM is a membrane permeable probe and can be easily loaded into cells by passive incubation. The probe is widely used in flow cytometry. For this application, it is critical to have an instrument with an argon laser tuned to UV or a heliumcadmium laser available. Wavelength Maxima: Excitation 346nm, Emission 475nm Alternative name: 1-[2-Amino-5-(6-carboxyindol-2-yl)phenoxy]-2-(2'-amino-5'-methylphenoxy)ethane-N,N,N',N'-tetraacetic acid, pentaacetoxymethylester. Purity: ≥95% (HPLC). Solubility: Soluble in DMSO. Long Term Storage: -20°C.