Across the world, freezers and cabinet shelves are full of human samples.
Biobanks — collections of biological material set aside for research — vary tremendously in size, scope and focus. Samples can be collected from the general population, from patients who have had surgery or a biopsy and from people who have recently died. Some collections date back decades. The Aboriginal genome, for instance, was sequenced from a lock of hair originally given to British ethnologist Alfred Cort Haddon in the 1920s; he crisscrossed the world gathering samples that are now housed at the University of Cambridge, UK. Most collections contain dried or frozen blood, but tissues such as eye, brain and nail are also held. Some biobanks address different questions from others: a population-based biobank that collects dried blood and health data may be used to determine the genetic risk factors for breast cancer, whereas a disease biobank that collects tumour samples might be used to reveal different molecular forms of breast cancer.
The number of tissue samples in US banks alone was estimated at more than 300 million at the turn of the century and is increasing by 20 million a year, according to a report1 from the research organization RAND Corporation in Santa Monica, California. Those numbers are probably an underestimate, says Allison Hubel, director of the Biopreservation Core Resource at the University of Minnesota in Minneapolis.
Seeing is believing
The cornea is one of the most important parts of our body because it enables our power of sight. It is also one of the most common parts of our body to break down over the years.
“The cornea is the most commonly transplanted tissue in the country, far more commonly than kidneys, or hearts, or lungs, or anything else that is transplantable,” said University of Minnesota mechanical engineering professor Allison Hubel. “About 44,000 individuals a year get corneal transplants and with the population aging that need will only continue to grow.”
Professor Hubel’s nanotechnology-enabled research to develop an artificial substitute for the cornea becomes more important every day.
Located in hospitals, universities, nonprofit organizations, and pharmaceutical companies, biobanks play a quiet but crucial role in health care. Like libraries of the human organism, they archive a wide range of biospecimens—including blood, hair, sperm, saliva, plasma, whole organs, and purified DNA—to use in research and experimentation. From drug development to assisted reproduction, progress in dozens of fields would be impossible without biobanks. They are the biological back end of data-driven medicine.
When the NCI drew up its plans for the atlas, dozens of bio-repositories in the US assured the institute that at least 500 samples of each type of tumor could be provided easily. Once the project was under way, however, the researchers got a series of bruising reality checks…
…The industry’s response to these revelations was a series of cautious upgrades. Adding a dose of enzymatic inhibitors to the preservative mix can reduce unexpected bouts of cell death but does nothing to eliminate DMSO toxicity. Chilling tissue at a carefully controlled rate immediately after harvesting (using a technique appropriated from Eskimos in the early 1900s by Clarence Birdseye, father of the frozen-food industry) reduces the need for toxic antifreeze but requires disruptive changes in the routine of overworked hospital staff.
These incremental solutions are hardly enough to make up for a long period of complacency. “We got stuck for about 20 years,” says Allison Hubel, a cryopreservation expert at the University of Minnesota. “People assumed that things like DMSO were one-size-fits-all solutions. If you have the perception that all the big problems in a field have been solved, there’s no motivation for funding.”