Our Frozen Legacey

With 30% of all land and aquatic animals predicted to go extinct within the next 50 years, the earth faces a biodiversity crisis not seen since the extinction of the dinosaurs. Museums like the Natural History Museum have therefore become involved in a race to preserve as much of the world’s genetic resources before they are lost.

Opened in 2012 as a joint venture between the British Government and Wolfson Foundation, the Molecular Collections Facility at the Natural History Museum is a ‘biobank’ of non-human biological material, such as tissue, DNA and RNA. As a not-for-profit repository, the collections are made available to scientific researchers across the globe to advance research into endangered and extinct organisms, some of which may assist in answering the way we solve the biodiversity crisis facing us. Along with other renowned museums such as the American and Smithsonian Museums of Natural History, the Molecular Collections Facility is part of the wider Global Genome Biodiversity Network. This global network of scientific institutions help in sharing the huge workload involved in extracting the molecular samples from the traditional collections displayed and stored in our museums.

Auditing the museum’s historic collections for biological samples of sufficient quality to be stored in the Molecular Collections Facility’s collection is no easy process. With many of the museum’s collections having been stored in sub-optimal conditions for the preservation of DNA and other biological material, the Molecular Collections Facility must provide storage solutions that will enable the samples to be viable for hundreds of years to come. Along with ‘repairing’ rare DNA samples that have been degraded with time. This preservation problem also transposes to modern fieldwork. For example, just how do you transport tissue samples back to London when on a 7 week expedition deep in the jungle of Vietnam without using chemical preservatives and avoiding excessive heat and humidity, each of which act to degrade molecular material? For this reason, time is of the essence, and along with developing secure and reliable ‘cold chains’ the Molecular Collections Facility has also to keep up-to-date with fast changing legislation relating to the collection and export of biological samples and dangerous goods.

With a capacity to hold 2 million samples, the Molecular Collections Facility faces the same problems as every museum collection, with space and time being two of the biggest. The colder and drier the storage environment, the better the likelihood that a biological sample will be stored successfully. Hence, the Molecular Collections Facility houses three large liquid nitrogen tanks each of which can hold 120,000 individual samples. Stored in datamatrix encoded cryopreservation tubes at -196ºC, this is the ‘gold standard’ for the long-term preservation of the molecular samples. In addition to the ‘gold standard’, thirty one traditional upright freezers are used to house historic samples stored in alcohol or as a ‘handling station’ prior to long-term liquid nitrogen storage. Along with ‘cold storage’, the Molecular Collections Facility is also developing techniques to store DNA at ambient temperature on paper impregnated with chemicals which capture and preserve the DNA from cells. Whilst a liquid nitrogen tank can store 120,000 samples and an upright freezer a mere 60,000 samples, paper storage enables 200,000 samples to be held in one storage drawer not much bigger than a kitchen utensil drawer. With 133 years of specimen collections to catalogue, one of the key tools in the Molecular Collections Facility’s success is automation. Without this, reformatting the DNA samples would take hundreds of years to achieve by hand. DNA extraction, purification and quantification are all automated processes and enable up to 384 samples to be handled at the same time, so reducing the reformatting time of the museums historic collections to only 5 to 10 years.

One other problem associated with long-term storage is how to you ‘track’ your samples? Would you risk an incredibly rare sample for hundreds of years to come to an adhesive label or number written on the tube in marker pen ink? Instead, the Molecular Collections Facility keeps all its cryogenically stored samples in tubes with laser-etched datamatix codes. These 2 dimensional barcodes provide each sample with a unique identification number which when used in conjunction with a Laboratory Information Management system, enables unique identifying data relating to each sample to be stored electronically and the samples’ location and history to be fully logged. With scientific advancement occurring so rapidly, the Molecular Collections Facility is also involved with initiatives in readiness for research beyond DNA. Examples include holding a growing collection of cryopreserved samples of living cells as part of the Frozen Ark, an initiative to biobank samples taken from endangered species. Currently being catalogued is a collection of 50,000 whole specimens of insect pollinating species, such a bumble bees, that are increasingly threatened by changes in the climate, habitats and agricultural methods. 

With the planet’s non-human organisms threatened as never before, the race to collect and catalogue their genetic and molecular resources is one that is not only huge in its undertaking but also subject to the pressures of time. The Natural History Museum through the Molecular Collections Facility is not only continuing the historic and world famous collection of specimens, but in a reversal of traditional roles is now acting in tandem with the world’s most prestigious institutions to provide a legacy to future generations, in the hope that they can learn from the mistakes that human expansion has placed on the other organisms that share this planet.

Dr. Gary Kennerley

Greiner Bio-One Ltd.

We would like to thank the Natural History Museum, and in particular all the staff of the Molecular Collections Facility, for their assistance in producing this article.

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