Liquid Nitrogen Cooling
Steve Deal, associate director for U.S. commercial operations for The Automation Partnership (TAP), talked about how TAP is addressing one of the major challenges in using robotic sample-handling devices in a sample-storage system. The company’s solution to the problem that mechanisms do not function at -80ºC is a box-within-a-box system that allows the bots to operate at -20ºC, while minimizing sample exposure to higher temperatures. The system also minimizes operator exposure to lower temperatures, according to Deal.
“When someone opens the door of an upright freezer commonly seen in hospital and pharma laboratories, the first thing that happens is the -80ºC temperature falls out into the warmer area, and samples are exposed to warmer temperatures that have a potentially negative impact on the samples,” said Deal. “With sample integrity in mind, TAP developed a patented drawer-access system that utilizes individually sealed drawers rather than a single large-door design. Thus, only a single drawer needs to be open at any time in order to pick or place samples.”
TAP’s flagship system is based on liquid nitrogen cooling, not mechanical cooling. This has a number of advantages. One is that it’s possible to achieve a true -80ºC temperature. Mechanical cooling systems generally either fall short or are working hard to get that cold. Another advantage is that energy usage is actually lower, which reduces cost and is a more environmentally friendly solution.
Mechanical refrigeration is still available from TAP, if that suits the customer’s needs better, but the liquid nitrogen system represents its most cutting-edge technology, and from a long-term perspective is less likely to become outdated.
A completely different take on biostorage comes from GenVault. David Wellis, Ph.D., president and CEO, gave a presentation on his company’s storage technologies.
For many years, the state of the art for biobanking has been cryostorage. But considerations of cost, energy usage, and standardization led GenVault to think outside the box and tackle dry room-temperature storage.
Dry room-temperature storage of samples is a practice dating back to the discovery of DNA itself. Rosalind Franklin and Maurice Wilkins, codiscoverers of the structure of DNA, used dry room-temperature handling techniques, which improved the resolution of their images the more the humidity was reduced.
DNA is surprisingly stable when stored this way, and, according to Dr. Wellis, GenVault has updated the method for the twenty-first century for a simple and energy-efficient small- to large-scale biobanking strategy. It also has a new chemical matrix, Gentegra, launched in September of 2008, to stabilize purified DNA and, soon, RNA molecules for room temperature storage.
GenVault’s technology has attracted interest from institutions such as the CDC and the Health Ministry of Canada. In the latter case, in a comparison of GenVault’s dry-storage technology with traditional cold storage and dry-ice shipment, it was found that the dry method was better at preserving the blood-borne antigens of interest, Dr. Wellis explained.
GenVault also includes a molecular bar code, Gencode, to augment a conventional bar code based sample-management system. Gencode is a series of unique oligonucleotides that travels with the sample, and can be checked independently of other sample ID information. Human error is a major source of error and information loss in sample management, largely unacknowledged by science but critical for law enforcement and diagnostic applications.
“We cannot yet replace all types of freezer-based sample storage,” said Dr. Wellis. But, for those types of samples that work well at room temperature—they can happily coexist, enhance, and back-up traditional freezers for a mixed-phase biobank.”
The establishment of a biorepository is a bet that there will be better uses for your samples in the future, and better ways to extract that information. There are already many examples of the value of biobanking, such as the discovery of Gleevec through the exploitation of Novartis’ biorepository. In addition, many of the technologies for analysis of samples are advancing at an incredibly rapid rate. Whereas in the past, sequencing of a large number of samples was inconceivable, now next-generation sequencing technologies are bringing that dream closer to reality.