New species, particularly isolates used to name species to expand our collection of type cultures.
Poorly represented strains of in species of the collection (to broaden population-level diversity).
Collected from new geographic locations, especially areas previously unexplored by collectors, to broaden geographic diversity in the collection.
Strains pre-screened by industry for commercial application (to preserve organisms that can promote business).
Organisms relevant to ongoing (and possibly future) research but which are in danger of being lost forever as programs change or end.
Organisms with unique genetic qualities that make them interesting for future research such as dimorphic species, mutants, species retaining ancestral polymorphisms, or even potential cryptic species (same morphology, different genotype).
Reference or model organisms in a broad range of comparative studies, such as Rhizophagus irregularis in the genome project and Diversispora epigaea in gene expression studies.
Obtained from novel or extreme habitats such as freshwater or salt-water wetlands; polluted lands; soils high in salts, phosphorus, acidity, or alkalinity to broaden ecological diversity.