Fig. 6. CR-geNOp, a ratiometric NO probe based on two FPs.
(A) Schematic structures of CR-geNOp consisting of the cyan FP (CFP), a NO-sensitive GAF domain, a rigid linker (EAAAK)n and the red FP (tagRFP) in the presence and absence of NO, which quenches CFP fluorescence only (B) Left panel: fluorescence intensity CFP (cyan curve) and RFP (red curve) over time in cells expressing CR-geNOp. Cells were treated with 10 μM NOC-7 as indicated. Right panel: respective ratio signal (red/cyan; F584/F480) of CR-geNOp (n = 98/5). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)