A cell permeable analog of BAPTA that binds calcium only after the AM group is removed by cytoplasmic esterases; commonly used at 10-100 μM to evaluate the role of intracellular calcium in cell signaling; also inhibits Kv channels, including Kv1.3, Kv1.5, and Kv11.1 (Ki = 1.45, 1.23, and 1.30 μM, respectively)