The fast development of molecular biology and other intensive analytical technologies has resulted in a dramatic increase in the need for biological sample storage.
Specimens of blood, serum, and tissue hold the key to the understanding of biological processes and represent valuable intellectual property.
Storage of biological and medical specimens that contain the raw information must be done under the strictest standards. The way you store your preclinical study materials must not permit contamination or allow the decomposition of the structures that hold vital medical and biological data. Poor storage management could represent a tragically missed opportunity for researchers who work to exploit the value of archived samples.
FDA Best Practices:
The Federal Food and Drug Association Center of Biologics Evaluation and Research [Guidance for Industry, Current Good Tissue Practice (CGTP) and Additional Requirements for Manufacturers of Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps), December, 2011] established compliance guidelines in a 60 page document that forms the basis for good tissue storage practice.
FDA Best Practices:
Best facility-wide practices include:
- Proper training and certification of staff handling biological samples.
- Carrying out regular quality audits of the storage facility and assuring the quality of original samples obtained for storage on receipt.
- Validation audits of any software used by the storage facility to avoid faulty timing or faulty references of samples.
- Physical structures in the storage facility must be of "suitable size, construction, and location to prevent contamination of HCT/Ps….and to ensure orderly handling. This includes lighting, ventilation, plumbing, drainage, and access to sinks and toilets that are adequate to prevent the introduction, transmission, or spread of communicable disease."
- A cleaning program using a demonstrably effective broad-spectrum disinfectant should be followed and documented.
- Environmental conditions have to be monitored and regularly documented.
Cold-Chain Logistics and Management:
The International Society for Biological and Environmental Repositories (ISBER) has developed detailed guidelines for the storage of biological study materials.
High standards of documentation, maintenance, and calibration also apply to the transportation of samples. As samples are being acquired from sources at greater distances than ever, high standards of global cold-chain management have to be maintained even before proper materials storage is considered. Expertise in logistics management has to be a part of good study materials storage. Samples have to be correctly packaged and monitored during shipping. Documents must be checked at each transfer point.
Quality storage includes standard operating procedures and business continuity plans in anticipation of power failures or discontinuities, not only in transportation but within the storage facility itself. Redundant measures like backup power with regular load tests are essential to ensure the integrity of samples. Computer systems that control the storage process or the scheduling of time-sensitive procedures have to be backed up with data stored off-site.
Many repositories of biological materials accommodate hundreds of freezers and temperature-controlled units. This equipment generates a lot of heat. HVAC systems have to be stable and powerful enough to compensate for heat generated in the facility.
Temperature: a critical component of storage:
In 2012, the Harvard Brain Tissue Resource Center, the largest federally-funded brain biobank lost one-third of its autistic brain specimens because of a faulty mechanical freezer. The storage protocol called for half of the specimens to be stored in formaldehyde and the other half in a freezer that was supposed to maintain -80 degrees C. The frozen specimens were lost when the freezer temperature reached 8 degrees C.
The three main storage categories are Ultra low, Refrigerated, and Ambient Storage
Ultra Low is a standard that can be achieved in mechanical freezers that can maintain between -70 degrees C and -80 degrees C. Biomarkers can be maintained at temperatures in this range.
Refrigerated Storage is a safe storage range for many biospecimens. This range is between -20 degrees C and +5 degrees C. Many enzymes and antibodies loose their functional activity and structure when they are repeatedly frozen and thawed. Therefore these sensitive sample types are stored at slightly above freezing temperatures, usually around +2 degrees C.
Ambient Storage is in the range between 15 degrees C and 27 degrees C. Tissue samples stored in a formalin fixed paraffin block or cut and mounted on slides are typically stored at room temperature, where temperature fluctuations are controlled.
HSRL provides the highest quality bioanalysis and specimen storage services. Our staff is committed to scientific integrity and superior responsiveness to client needs. Please contact us to find out more.