Next-Gen Brain Freeze
Use of frozen tissue remains the method of choice for characterizing the genome, transcriptome, and proteome. This method, however, is costly and displays temperature-related degradation differences among nucleic acids that must be taken into account. It’s also far from foolproof, as researchers from the University of California, Los Angeles (UCLA) have emphasized.
In the May 2014 issue of Clinical Biochemistry, these researchers revisited the case of a freezer failure, apparently undetected by redundant alarm systems, that damaged one-third of the specimens in a national autism brain bank and numerous other brain specimens.
“Storing samples in liquid nitrogen (LN2) poses rare but serious risks including LN2 burns, LN2 supply tank explosions, and suffocation from LN2 leaks in an enclosed space,” the authors wrote. “Finding adequate contiguous and practical space for banks of freezers or liquid nitrogen vats is extremely challenging at major medical and research institutions.”
William H. Yong, M.D., Brain Tumor Translational Resource at the David Geffen School of Medicine, UCLA, one of the authors of the UCLA study, is scheduled to deliver a presentation at the Biobanking Congress.
“Frozen biospecimens, while superb for next-generation testing, are costly. In the current environment, increasing the collection and storage of such specimens is not sustainable,” says Dr. Yong. “While next-generation technologies are being developed to work within the limitations of FFPE, the limitations cannot be entirely overcome.”
Nonetheless, Dr. Yong remains optimistic: “I believe that investment by national funding bodies and pharmaceutical institutions in developing broadly usable room-temperature biospecimen alternatives that permit high-quality whole-genome, transcriptome, proteome, and metabolome analyses will be rewarded by larger, more affordable pools of patient biospecimens for clinical trials of targeted therapy.”
Dr. Yong’s talk will focus on brain tissue, but it is likely that much of his talk’s content will be derived from the UCLA overview he helped prepare. This overview, entitled “The procurement, storage, and quality assurance of frozen blood and tissue biospecimens in pathology, biorepository, and biobank settings,” addressed the following questions:
How quickly must we freeze a biospecimen?
Is the ubiquitous –80°C freezer really adequate to stabilize biospecimens, or is –150 °C storage superior?
How much does freeze-thawing, as occurs with removing specimens from freezers repeatedly, affect biospecimen degradation?
What is the basis for the quality assurance methodologies currently in use?
The overview not only reflected an attempt to organize the fragmented and incomplete data on procurement and preservation of frozen biospecimens, it also summarized “infrastructure considerations for frozen biospecimen banking.”