Cal-590(TM), potassium salt

Calcium measurement is critical for numerous biological investigations. Fluorescent probes that show spectral responses upon binding calcium have enabled researchers to investigate changes in intracellular free calcium concentrations by using fluorescence microscopy, flow cytometry, fluorescence spectroscopy and fluorescence microplate readers. Rhod-2 is most commonly used among the red fluorescent calcium indicators. However, Rhod-2 AM is only moderately fluorescent in live cells upon esterase hydrolysis, and has very small cellular calcium responses. Cal-590(TM) has been developed to improve Rhod-2 cell loading and calcium response while maintaining the spectral wavelength of Rhod-2, making it compatible with TRITC/Cy3® filter set. In CHO and HEK cells Cal-590(TM) AM has cellular calcium response that is much more sensitive than Rhod-2 AM. The spectra of Cal-590 is well separated from those of FITC, Alexa Fluor® 488 and GFP, making it an ideal calcium probe for multiplexing intracellular assays with GFP cell lines or FITC/Alexa Fluor® 488 labeled antibodies.