Samples and associated data are stored using methods to protect their value to researchers, while simultaneously ensuring that the “chain of trust” begun with the donor is maintained. This chain not only includes an expectation of privacy for donors and the confidentiality of their data, but also an expectation that their gift will be valued and used to further biomedical research.

Sample storage

Samples come to biobanks in multiple formats with multiple requirements for safe and long-term storage.

The most common format for solid tissue samples is one used in standard pathology, where the sample (usually between ¼ and ½ inch in most dimensions) has been preserved in a fixative called formalin (like formaldehyde) and then embedded in paraffin wax. The wax chip is held in a plastic cassette that is useful for manipulations, such as cutting thin sections off for placement onto glass microscope slides. These wax-embedded samples are stored at room temperature in controlled humidity.

Another common format is tissue that has not been fixed in formalin, but was quickly cryogenically frozen to preserve it. Such tissue might also be embedded in a special material that allows it be cut when cold. Such frozen material, as well as living cell lines, is usually stored at -86 deg. C in freezers or at -196 deg. C in liquid nitrogen.

The other very common type of tissue is blood or blood components (such as serum) stored frozen in vials. Other types of samples potentially include small amounts of solutions of biochemicals from tissue, dried down samples, or samples imprinted onto membranes. Storage environments for these and other materials will include room temperature, 4 deg. C, and -20 deg. C.

As described above, a large biobank deals with many tissues and biochemicals, in many formats, with many samples being moved from shipping and receiving, storage, and laboratories everyday. Since everything must be tracked, samples will be barcoded for scanning at many steps during their processing, and all accesses to storage locations will be logged. Every storage unit is highly organized and compartmentalized, with every sample occupying a unique and computer-tracked location.

Because the biobank is a custodian of such valuable materials, it must address many safety and disaster prevention issues. Among such challenges are backup power, backup cooling if power is out, security and physical access restrictions, and preparations for potential natural disasters such as earthquake or flood.

Data storage

The data that accompany biospecimens in the biobank are stored in computer systems that run complex database management and analysis software. Such information includes not only the clinical data from the donor’s medical record, but all the tracking, logistics, and quality control data as well.

A key feature of the clinical data is that it is converted from the more free (unstructured) form as it existed in the medical record to a highly structured form based upon standards and values that are “machine readable.” This term means that the data at the biobank have been converted to a form that is easier for computers to interpret, which aids in querying large databases, doing statistical calculations, and distributing that data to researchers who are receiving samples from the biobank.

Several steps are typically taken for data security and data integrity. For example, the computer systems are built with redundant hardware – along with backup power – and data protection schemes so as to minimize the risk of data loss. Such processes might include ensuring that all data backups be encrypted; that keys linking donors’ identification to their biobank-assigned number be held by a third party; and that all access to the database be logged. In addition, security procedures would ensure that the computer systems are not directly connected to the internet, and that user access restrictions are in place.