Membrane-impermeant calcium indicator that can be loaded into cells via microinjection or scrape loading. For the membrane-permeable AM ester form of Rhod-590, see 50025.    Kd: 0.61 uM  &lamba; Ex/&lamba; Em  590/616 nm for zero calcium and 595/626 nm for high calcium  Purple solid soluble in DMSO and water (pH >6)  Store at 4°C and protect from light, especially in solution  MW: 1029