Fig. (3) Detection of acid phosphatase activity with CF-MUP and MUP. For the top and bottom curves MUP and CF-MUP were incubated with acid phosphatase buffer at pH 6.0, and the resulting fluorescence signal was recorded with Ex/Em=360 nm/450 nm without pH adjustment. For the middle curve, MUP was incubated with acid phosphatase buffer at pH 6.0, and the enzyme reaction solutions were adjusted to have pH = 10 by 1 M NaOH alkalization. The resulting fluorescence signal was recorded with Ex/Em=360 nm/450 nm.