Fern Sorus Thin Section

G-2A Longpass Emission (Wide Bandwidth Excitation) Green Set

Autofluorescence emission intensity from a fern (Holly; Cyrtomium caryotideum) sorus indusium. Endogenous autofluorescence in plant tissues arises from a variety of biomolecules, including chlorophyll, carotene, and xanthophyll. In the green excitation region, chlorophyll has an absorption band with a low extinction coefficient, but still produces a detectable level of fluorescence at emission wavelengths of 550 nanometers and above (green, yellow, orange, and red). For the fern thin section illustrated above, note the presence of autofluorescence emission intensity in the orange and red spectral regions.