Hello,

why not try the method of "Gould KS, Lamotte O, Klinguer A, Pugin A, Wendehenne D". Nitric oxide production in tobacco leaf cells: a generalized stress response? Plant, Cell & Environment. 2003;26:1851-62.

If ever you don't have adobe photoshop, image J (free) may be useful.

Good luck

Sanders

Dear Ioannis,

Sanders answer is fine. The team of Pradeep Kachroo  also used an interesting approach (see the Cell report attached to this answer) : they added DAF in the homogenates of tissue extracts followig pathogen exposure and then measured the fluorescence. This approach ensures that the quantity of the fluorophore is  similar in all the assays and give quite robust data when comparing different treatments and/or genotypes. In contrast, assay based on infiltration of DAF in living tissues relies on the assumption that fluorophore diffuses similarly in all the leaves/genotypes and therefore is not as reliable.

All the best,

David