Raman Technique Helps Evaluate Pollen

Pollen counts and subsequent allergy warnings are currently based on visual identification of pollen grains examined under a microscope. This painstaking technique is not particularly helpful for allergy sufferers who react to one kind of pollen but not another and would prefer to know more quickly what type of pollen is airborne at a given time. Janina Kneipp of Humboldt University of Berlin, in Germany, and colleagues have found a way to speed up pollen identification by using a Raman spectroscopy technique that could make real-time, automated pollen analysis and warnings feasible (Anal. Chem. 2008, 80, 9551). The researchers collected Raman spectra of pollen from 15 tree species. The spectrum of each pollen sample consists of superimposed signals from a variety of biomolecules, such as nucleic acids, lipids, and proteins. Together, those signals provide a chemical signature for each type of pollen. The researchers showed that the technique can quickly distinguish pollen grains from maple, birch, and other trees.