(a) CuFL1 detection of NO in SK-N-SH neuroblastoma cells. [CuFL1] = 1 μM, [17β-estradiol] = 100 nM. From left to right: 25 min exposure to CuFL1, no 17β-estradiol; 5 min; 10 min; 15 min; 25 min exposure to CuFL1 and 17β-estradiol. Top: Fluorescence images; Bottom: DIC images. Scale bars = 50 μm. (b) CuFL1 detection of NO in Raw 264.7 murine macrophages. [CuFL1] = 1 μM, [lipopolysaccharide (LPS)] = 500 ng/mL, [interferon-γ (IFN-γ)] = 250 U/mL. From left to right: 12 h exposure to CuFL1, no LPS/IFN-γ; 6 h; 8 h; 10 h; 12 h exposure to CuFL1 and LPS/IFN-γ. Top: Fluorescence images; Bottom: DIC images. Scale bars = 50 μm. For additional details see ref. 32