Founded in 2011, the Smithsonian National Museum of Natural History Biorepository (NMNH) is thought to be the largest museum-based natural history biorepository in existence. The capacity exceeds 4.2 million 2 ml cryovials, with potential for expansion to 5 million cryovials. Dating from the early 1970s the NMNH research team have collected material for projects in biodiversity, phylogenetics, population genetics, toxicology, environmental monitoring, and more. The recent explosion of genomic science such as the Earth BioGenome Project has increased the value of these materials and the rate of genomic collection growth. It is aimed that all archival genomic collections of the NMNH will be centralised to the Biorepository. The NMNH notes that researchers interested in free, permanent, archival storage of DNAs, tissues and phenotype vouchers of genomic research and collections should contact them.
The two main types of freezers in use at the Biorepository are mechanical and liquid nitrogen. The freezers use a “cascade refrigeration system”, which employs two different refrigerants with different boiling points. The mechanical freezers at NMNH are unusual in that they use water to cool the compressors, unlike most freezers that use ambient air to cool the compressors. This reduces the need for air conditioning, which makes the facility “greener”. The liquid nitrogen freezers work on a different principle, the material in vials is stored in a large rotating rack above a pool of boiling liquid nitrogen approaching -190°C. All the freezers and refrigerators in the Biorepository are continuously monitored by an electronic system allowing remote monitoring that calls responders during an outage or emergency.
The Biorepository supports genomics and other non-commercial research endeavors by providing materials which can be obtained by first contacting the pertinent NMNH Science Department. The Biorepository is also very interested in preserving additional material, tissue and DNA from organisms used in genomic studies.