Biorepository

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Human Tissue Samples Used in Biobanks

Introduction

Biobanks are centers that process, organize, and maintain biospecimens that would be used in various clinical and research-based purposes. There are many different types of biobank. That is why before starting a biobank, the goals of the biobank should be delineated. Accreditation and standard operating procedures are also crucial to ensure the biospecimens are of the highest quality as compromised biospecimens can negatively affect the results of clinical studies or research. Other important factors include developing a budget and obtaining funding sources to warrant that the designated space, equipment, and personnel necessary are acquired. Another critical part of the biobank would be the laboratory information management system. Extra effort should be expended to guarantee the security and effectiveness of the system. 

Operations

Biobanks are part of the research infrastructure as they provide samples for various purposes. The samples are randomly collected and compiled into categories such as based on diseases or therapies. It is vital that the sample characteristics are preserved with minimal alterations during the collection, processing, and storage stage. Degradation processes begin shortly after the specimen is obtained from the host. There are some factors that may contribute to the degradation process such as the lack of oxygen supply. The gold standard during the collection process is to collect the samples in a standardized method and to minimize the duration from harvesting to freezing. Samples can be collected during routine clinical procedures or from the remains after diagnostic procedures. Since samples are collected randomly, complete standardization of the preanalytical procedures may be impossible. 

To minimize variability, some methods include:

  • Ensure that the duration from sample acquisition to freezing is kept as short as possible

  • Standardizing handling of samples once it has arrived at the biobank

  • Standardize the use of protective reagents

RNAlater

RNAlater is a high salt ammonium sulfate aqueous solution that is used specifically to stabilize RNA in tissue. This solution precipitates the RNAses depending on the concentration and pH. Some studies have shown that the expression profiles are well preserved in RNAlater compared to shock frozen tissue. This is exceptionally true for some genes when measured using real-time polymerase chain reaction (PCR) and also for RNA expression microarray analysis. Through RNAlater stabilized tissue, DNA that is suitable for PCR can be extracted. Tissue specimens preserved using RNAlater can also be sectioned on a microtome and later, stained for histological analysis. Further major advantages of using RNAlater includes:

  • Omitting the use of expensive and dangerous liquid nitrogen

  • Direct placement of samples into the preserving agent right after extraction

  • Stabilization of nucleic acids such as RNA

However, it is important to note that the preservation of samples is not as abrupt compared to shock freezing in liquid nitrogen since RNAlater will need to diffuse into the samples. The samples will need to be incubated in the reagent for a minimum of 24 hours to confirm that there is enough absorption before freezing. Another added benefit of RNAlater preserved specimens is that samples remain protected even after freezing and thawing while snap-frozen tissue samples that thaw lead to degradation of RNA as the process destroys intracellular compartmentalization. This benefit minimizes the effect of temperature changes and makes sample handling much easier.

Human Biospecimens and Ethical Issues

One of the most prominent ethical issues with human biospecimens is consent. In a case involving the biospecimen of a woman known as Henrietta Lacks from Virginia, some of her cells were taken without consent during her treatment for cervical cancer. Her biospecimen subsequently played a role in decades of research which led to gene mapping, the creation of the polio vaccine, and cloning. Despite having many parties involved making a lot of money from the cells, Henrietta Lack's family never received any compensation, nor did they have any knowledge about her role in it until 25 years later. This case highlights a problem that still persists today. Many individuals do not realize that when they are donating their samples such as tissue or blood to science. Most consent obtained is "broad consent” where participants agree that their materials and information would be used without being given any additional details. 

Another major issue is those involving ownership of the specimens. A study published in 2014 found that there was no consensus regarding who the samples belong to. While the participants believe that the biospecimens belong to themselves, researchers think that it belongs to the institution. It is a difficult situation as donors will lose trust in the system if biobanks continue to partner and commercialize with private companies. In 2009, a group of parents in Texas filed a lawsuit regarding the banking and use of samples obtained from their children as they never consented for the samples to be used for experimentation. When the court ruled in the parents’ favor, it led to the destruction of millions of research samples. 

References:

  1. Lindner M, Moressi-Hauf A, Stowasser A, Hapfelmeier A, Hatz R, Koch I. Quality assessment of tissue samples stored in a specialized human lung biobank. PLOS ONE. 2018. Accessed 4/23/2019. https://www.biorxiv.org/content/10.1101/407411v1.article-info

  2. Harati MD, Williams RR, Movassaghi M, Hojat A, Lucey GM, Yong WH. An introduction to starting a biobank. Methods Mol Biol. 2019; 1897: 7-16. 

  3. Dube J. “Biobanks” that store human blood and tissue have a consent problem. Motherboard. Accessed 4/23/2019. https://motherboard.vice.com/en_us/article/bjx49w/biobanks-that-store-human-blood-and-tissue-have-a-consent-problem