Biological Ice Nucleation Magdalena Bichler a, Laura Felgitsch a, Verena Seidl-Seiboth b, Hinrich Grothe a a Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9/BC/01, 1060 Wien b Institute of Chemical Engineering, Vienna University of Technology, Gumpendorferstraße 1a, 1060 Wien According to Huffman et al. [1] a burst of biological ice nuclei (IN)can be found over woodlands during and after rain events. The origin of these particles can be e.g. bacteria(e.g. Pseudomonas syringae), fungi (e.g. Fusarium acuminatum spores), and(decayed) plant litter. Previous investigations in our group [2] showed that both pollen and pollen washing water from plants originating from the northern timberline show ice nucleation activity. These facts suggest that other parts of the plants might also act as IN due to their cold protection and cold tolerance mechanisms. We extended our investigation to other parts of the plants and further biological materials such as both waterinteracting and structural polysaccharides, like pectin and chitin, as well as chemical modifications of these polysaccharides. Of particular interest concerning plant parts are berries, such as sea buckthorn and blackcurrant. We examined the ice nucleation activity of both juices of berries found near the northern timberline and extracts of these berries. ____ [1] Huffman et al., Atmos. Chem. Phys., 13, 6151-6164, 2013 [2] Pummer et al., Atmos. Chem. Phys., 12, 2541-2550, 2012