Rhod-2 (sodium salt) is a water-soluble, red fluorescent calcium indicator. It exhibits a significant shift in fluorescence intensity upon calcium binding (ex max = 549 nm; calcium-free v. ex/em max = 552/581 nm; calcium-bound). Unlike the UV-excitable indicators fura-2 (Item Nos. 19531 | 20414) and indo-1 (Item Nos. 20419 | 20418), there is no accompanying spectral shift.
