BTC is a low affinity calcium indicator (K
d = 7-26 μM) that displays excitation/emission spectra of 401/529 nm, respectively. It exhibits a shift in the excitation maximum from approximately 480 to 401 nm upon calcium binding, enabling determination of ratiometric calcium measurements.
1 BTC is suitable for detecting elevated calcium levels associated with activation of smooth muscle, neurons, and intracellular calcium stores.
1,2
