BCCM/ULC is a small and dedicated public collection, currently containing one of the largest collections of documented (sub)polar cyanobacteria worldwide. The BCCM/ULC collection is hosted by the Centre for Protein Engineering (the Unit) of the University of Liège. The host Unit is very active in research projects concerning the cyanobacterial diversity and biogeography, with a focus on polar biotopes. The approach used is polyphasic, including the isolation of strains and culture-independent methods (DGGE, clone libraries, pyrosequencing based on the ribosomal operon sequences). The participation to field expeditions in the Antarctic and Arctic has enabled to collect samples in many locations.