Purity >95%. Fura-PE3 AM is the AM of fura-PE3, a non-invasive, intracellular calcium indicator that is UV light-excitable. Like fura-2 AM , this compound readily crosses cell membranes, where it is converted by cellular esterases to remove the AM group, leaving the calcium indicator. Fura-PE3 is comparable to fura-2 in its spectral properties, ion selectivity, pH insensitivity, and non-invasive loading capabilities. However, the addition of a sidechain containing piperazine allows fura-PE3 to resist the rapid leakage and compartmentalization seen with fura-2. As a result, loaded cells can be monitored for hours. Excitation and emission maxima for fura-PE3 are 364 and 508 nm, respectively, without calcium and 335 and 495 nm, respectively, with bound calcium.