Concentration-response curves (CRC) and Z′ comparison of known small-molecule SERCA effectors. (A) 16-point concentration-response curves show that thapsigargin, a specific SERCA inhibitor, induces a larger lifetime change for O/M (orange) than for G/R (green). (B) Z′ analysis of 2CS incubated with saturating dose of 200 nM Tg from 128 wells of a 1536-well-plate shows a larger response for O/M than for G/R. (C,D) 8-point CRC shows that SERCA inhibitors cyclopiazonic acid (CPA) and 2,5-di-t-butyl-1,4-benzohydroquinone (BHQ) also induce larger lifetime changes for O/M than for G/R.