MQAE (N-(Ethoxycarbonylmethyl)-6-methoxyquinolinium bromide) is an improved chloride indicator that has greater sensitivity to chloride (Ksv= 200M-1) than SPQ (Ksv=118 M-1) and higher fluorescence quantum yield. The ester group of MQAE may slowly hydrolyze inside cells, resulting in a change in its fluorescence response.    White solid soluble in water and DMSO  Store at 4°C and protect from light, especially in solution  &lamba;Ex/λEm= 350/460nm  ε (344 nm, H2O) = 2,800  C14H16BrNO3  MW: 326.19 [162558-52-3]