UV-2B Longpass Emission (Wide Bandwidth Excitation) Ultraviolet Set
Autofluorescence emission intensity from a thin section of fern (Cyrtomium falcatum) sporangia. Endogenous autofluorescence in plant tissues arises from a variety of biomolecules, including lignins, chlorophyll, carotene, and xanthophyll. In the ultraviolet region, chlorophyll has an absorption band with a high extinction coefficient and produces a significant amount of fluorescence when excited with wavelengths between 350 and 400 nanometers. Note the presence of spectral bleed-through from autofluorescence emission in the green and red spectral regions, which is strongly reminiscent of a darkfield image.