The advancement of modern research in the medical field is very much dependent on access to high-quality human tissue specimens. There are now various organizations that have the responsibility to collect, process, store, and distribute human tissues to help researchers involved in biomedical research. While there may be guidelines for best practices in tissue procurement, these guidelines are usually general and may not include all the details required by individuals or investigators who are new to using human tissues.
Tissue Procurement Model
There are various approaches to procure human tissues and fluids for research. Examples include:
• “Catch as catch can” model – This is one of the most disorganized methods often used. This method involves the cooperation of professionals such as pathologists and surgeons to provide tissue samples whenever they are available to researchers. These specimens are usually only collected when the request is remembered and when time permits. This also means that there is very little to no quality control as there is no standard protocol regarding the collection, processing, and storage of the specimen. Therefore, the quality of these specimens can be poor and may provide inaccurate results or data. Another issue regarding tissues that are obtained via this method is the oversight of Institutional Review Boards (IRBs) and may violate the regulations or requirements of the IRB or Health Insurance Portability and Accountability Act (HIPAA).
• Banking model - Another more organized approach would be to obtain specimens that are research-grade quality from organizations such as biorepositories or biobanks. These organizations usually have a standard operating procedure (SOP) when collecting, processing, and storing specimens. The collected tissues are usually frozen or stored in paraffin blocks. Fresh samples are generally not available. Therefore, the main disadvantage of obtaining specimens from organizations with the “banking model” would be not meeting custom requirements such as tissue size, percentage of tumor in the specimen, or requests for normal or fresh tissues. The advantages of using this approach would be the ability to obtain large numbers of specimens that have corresponding demographic and clinical information.
• “Clinical trial model” – This model is a subtype of the banking model. This method involves using the remnants of specimens that were collected from clinical trials. This main issue in this model would be that the original informed consent from the clinical trial may not allow the specimen to be used in other studies. Therefore, the IRB involved may limit the use of these specimens for different researches. The specimens from the clinical study may also be limited in both number and size. The method the tissues were processed for the clinical trial may not be suitable for the investigators.
• Prospective collection model – This method requires the investigators to specify the specimen they need and how they want it to be collected, processed, or stored. The main disadvantage of this model would be the unavailability of large numbers of specimens with its main advantage being the investigator acquiring what is requested. The investigator should realize that it may take a while for the specimens requested to become available.
• Tissue repository model – This is a combination of the banking and prospective model. This model includes the advantages of both models. The term “repository” is defined as “an entity that collects, processes, stores, and distributes specimens”. However, one of the main issues that a repository may face is the complex administrative needs and the increased requirements for an advanced bioinformatics system.
With more development of tissue repositories, the optimization of such operations is being monitored by the International Society of Biological and Environmental Repositories (ISBER) to help organizations that are operating biorepositories. Since there is little published information regarding operational support of biorepositories, ISBER published best practices guidelines to help maintain the expectations of the professionals in this industry. Best practices for tissue practices focusing on neoplastic diseases have also been published by the National Cancer Institute (NCI). These documents are crucial as they provide details for specific operations.
Quality assurance is crucial in all biomedical research as it helps improve operations, procedures, and products. Quality control refers to the technical activities measuring the performance and attributes of the process or product against current standards. Individuals responsible for quality assurance help in the development of new guidelines and to ensure that SOPs are followed. They also lead the efforts to identify and correct problems related to the collection, processing, storage, and distribution process. The minimum quality control for a biorepository should involve the examination of the tissue by a certified pathologist. It can also include a molecular analysis where DNA, mRNA, and protein are extracted. In more specific projects, a more extensive quality control examination can be requested. However, depending on the biorepository, there may be an additional price charged to their clients as extensive quality control involves increased time, effort, and cost.
Grizzle WE, Bell WC, Sexton KC. Issues in collecting, processing, and storing human tissues and associated information to support biomedical research. Cancer Biomark. 2010; 9(1-6): 531-549.