Pollen bring light into the darkness

A way of classifying pollen species is by monitoring auto fluorescence images of pollen grains. Several components of the exine (i.e. the outer layer of the pollen wall) show conspicuous auto fluorescence in the pollen grain.

The technique allows further morphological characterization of pollen (e.g. determination of pollen size and shape, and the number and type of apertures, the pattern of the exine, etc.), evaluation of pollen integrity, detection of additional components (e.g. the pollen coat) over the surface of the pollen wall, etc. The methods used can be considered non-disruptive and lack of sample preparation. Monitoring pollen auto fluorescence can be useful in disciplines like aerobiology, palynology e.g. in deposits of various type and age in order to determine age (for which conventional pollen analysis fails) and plant taxonomy.

As it is well known, pollen is a seasonal problem for millions of people around the world who suffer from allergenic reactions to the antigens embedded on the outer casing of these microscopic grains. The images presented reveal green auto fluorescence of Cucurbita and Lily pollen grains visualized utilizing blue light excitation fluorescence microscopy.