The ICSN Strain library is a collection of over 1 000 symbiotic microorganisms. Identification of fungi is performed by amplification of the ITS4 or ITS1 region of the rDNA and bacterial strains are identified from 16S rDNA sequence analyzes. The DNA sequences are aligned with those of GenBank, NCBI, using BLASTN 2.2.28 and have been deposited in GenBank for accession numbers. The strains are conserved in triplicate at -80 °C. Standardized extracts from these strains are prepared by culturing on PDA solid medium followed by extraction with ethyl acetate. All strain extracts are distributed in multi-well plates in order to be screened on different biological targets. The strain library is connected to a database containing all the information about collecting the microorganisms, strain host determination, identification, biological assays, and research programs for which each strain was isolated and/or identified, as well as the extracts generated. Some of these extracts are listed in the French National Chemical Library and can be consulted by the scientific community.