preservation of biological specimens: protocols, and best practices

In specimen collection, best practices focus on preservation of biological specimens through minimizing the effects of handling on biospecimen integrity. In general, factors that can influence biospecimen quality during collection, processing, and storage are defined as pre-analytical variables:

• Human physiology before the biospecimen collection - Biospecimen quality may be affected by overall health and the medication status of the patient/research participant, food and beverages consumed, as well as circadian rhythms. As a golden rule of best practices, pre-analytical variables must be notated for reference if they cannot be controlled; information about these factors should be collected and recorded to decrease the variability between samples.

• Collection practices - Preservation of the biospecimen as quickly as possible after removal from the patient is one of the key best practices during sample collection. It is also vital to annotate each specimen with the conditions of biospecimen collection, processing, and storage, according to Biospecimen Reporting for Improved Study Quality (BRISQ) or a similar collection of recommendations.

• Handling practices before downstream testing - Best practices also dictate optimization of biospecimen handling to minimize molecular changes that may result from the processing activities. Most critical factors in this stage include cold ischemia time (the time between biospecimen removal from the patient and its placing into fixative), temperature and timing of bioprocessing, the size and volume of the sample, as well as freeze-thaw cycles.

How Can Institutions Improve?

To aid with advancements in best practices related to biospecimens, programs such as the NCI’s Biospecimen Research Network and the Standardisation and improvement of generic Pre-analytical tools and procedures for In-vitro Diagnostics (SPIDIA) in EU are conducting original research to identify and address the major questions of biospecimen methodology before biospecimen testing. According to these findings, organizations should establish sample lifecycle management strategies that dictate how samples are collected, transported, processed, stored, documented and even archived for future use.

Advances in medical science are most often derived from properly-preserved biological samples and the clinical data linked to them. Preservation of biological specimens throughout their sample cycle is thus at the forefront of medical research.