Best Practice In Validating New Automated Sample Storage Systems At UZ KU Leuven Biobank

Pixabay License | Source: Philip Neumann , no changes made.

Biobanking is the cornerstone of the Precision Medicine Initiative guided by the director of the US National Institutes of Health, Francis S. Collins. Historically the process of getting samples from patients/ volunteers to storage (biobanking) has been the least standardized of all biomedical research procedures. Gene expression profiles change with time and temperature variation, for example. Reproducibility and comparability between research studies is key to fulfilling the promise of precision medicine. To this end biobank standard ISO 20387:2018 was developed to ensure quality, fitness-for-purpose, and reproducibility in biobanking to give translational researchers quality defined samples to work with.

Automating sample storage and retrieval can improve sample quality by standardizing the time required and the inherent temperature fluctuation. The samples at The Biobank of the University Hospitals and the Catholic University of Leuven (UZ KU Leuven), Belgium, is a centralized resource that contains samples of different types from a plethora of sources. In December 2013 two Brooks Life Sciences automated systems for frozen liquid biospecimens such as serum, urine and plasma were acquired, one for storage at −20◦C and one for storage at −80◦C.

It is best practice to validate/ benchmark such systems for performance before stocking samples for experimentation. Due to the nature of automation failure to do so could result in the loss of many high value samples, which may not be discovered immediately. Despite this no validation protocols for automated systems were available at the time, so a validation/qualification method for automated frozen sample storage systems was developed. This protocol is reported in a recent paper of the journal Frontiers in Medicine.

The system qualification and assessment test (SQAT) consists of recording the timing and operation of the input and output of a standard storage format containing simulated sample (water); sample input and scanning, sample reformat from standard density to high density trays, sample picking from high density to standard density trays and sample output and scanning. The SQAT took 15 and 20 min to complete for the two automated systems, respectively.

At UZ KU Leuven, over a period of 7 months, 30% of SQAT tests failed (n = 196) on the -80◦C system. The other system was deemed reliable and not tested further. The main causes of failure were imaging problems, tube picking malfunction and mechanical crashes.

These problems may have been due to incomplete installation and cooling system issues, leading to frost build-up. This highlights the importance of verifying complete and proper installation from the outset.

Upon adjustment of the installation and further testing, including temperature variation, the system was deemed reliable. Testing revealed the importance of selecting and verifying the compatibility of tubes and enforcing the maximum filling volume. Correct sample tray loading by the user was also found to be critical.

Upon validation the systems entered use in February 2018. As of January 2020 the stores held about 63,000 samples provided by three different research groups. The vast majority of which are serum (97%), followed by plasma (1.7%), and urine (1.3%). Regular assessments of SQAT and the loading error rate are used to monitor the systems which have functioned within their expected ranges since implementation. The systems were well received by users, but incur higher costs by necessitating adjustment of laboratory workflows to use compatible barcoded tubes.

The authors concluded, “The UZ KU Leuven Biobank devised a SQAT test to assess performance of the automated systems and set up a method for temperature homogeneity testing. Although these are tailored to our systems, the underlying concept is applicable to other automated storage systems as most of them share a similar basic concept regarding sample management and storage at a specific temperature.”