Abstract
Diaminofluorescein-2 (DAF-2) has been widely used as a fluorescent probe to detect the production of nitric oxide (NO) that functions as a signaling molecule in plants and animals [1,2,3]. We report here that the fluorometric NO detection with DAF-2 involves a potential risk to deduce wrong conclusions. As well as the NO indicator DAF-2, PTIO has also been applied to prove in vivo NO production through its specific scavenging activity. Most researchers have presumed that the NO scavenger PTIO should diminish the DAF fluorescence. However, we could not confirm such PTIO-dependent decrease in fluorescence, rather an increase in fluorescence in response to PTIO was observed. The results demonstrated shown here offer reconsideration for the previous reports that used DAF-2 in conjunction with PTIO.
[1] Kojima et al. (1998) Anal. Chem.70, 2446-2453
[2] Yamasaki (2005) Plant Cell Environ. in press
[3] Yamasaki & Sakihama (2000) FEBS Lett. 468, 89-92
