Figure 3.

A healthy pine needle showing flavonoid distribution. (a) Treated with Naturstoffreagenz A (NA) for 5 min showing localization of flavonoids (green) in the epidermis and hypodermis; (b) Untreated control at the same gain setting. The red fluorophore is chlorophyll. Sequential excitation at 488 and 561 nm with corresponding emission at 500–570 (green), and 570–700 nm (red). Scale bar = 100 µm.