As of 1 April 2026, the PSJD database will become an archive and will no longer accept new data. Current publications from Polish scientific journals are available through the Library of Science: https://bibliotekanauki.pl
Some relatively simple and cheap procedures for long term preservation in liquid nitrogen have been worked out.These are based both on two-step freezing (in which the specimen is progressively dehydrated when ice crystals grow in the medium during slow cooling) and on vitrification (absence of ice crystals due to rapid freezing in highly concentrated vitrifying solutions).For recalcitrant strains alternative storage methods have been studied.