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Licensed Unlicensed Requires Authentication Published by De Gruyter November 2, 2021

Total lab automation: sample stability of clinical chemistry parameters in an automated storage and retrieval module

Kobe Vercruysse ORCID logo , Stijn Lambrecht and Matthijs Oyaert EMAIL logo



Automated storage and retrieval modules (SRM), as part of total lab automation (TLA) systems, offer tremendous practical and economic benefits. In contrast to manual storage systems, SRMs indicate continuous motion of samples and may leave samples prone to temperature fluctuations. This study investigates analyte stability in serum and heparin plasma within an automated storage module.


The stability of 28 common biochemistry analytes was investigated using 57 freshly obtained routine serum samples and 42 lithium-heparin plasma samples. Following baseline measurement, samples were stored at 2–8 °C in the automated SRM of the Accelerator a3600 TLA and reanalyzed at fixed time points (2, 4, 8, 12, 24, 48 and 72 h) on the Abbott Architect c16000 chemistry analyzer. The concentration at each time point was expressed as %-difference to the baseline value and mean results were compared to the criteria for desirable bias derived from the biological variation database.


Nine of the analytes exceeded the bias criterion within 72 h after initial measurement in either serum samples, plasma samples or both. Lithium-heparin plasma samples showed increasing values for phosphor, potassium and lactate dehydrogenase (LDH), which were only considered stable for respectively 24, 12 and 4 h, glucose was considered stable for 8 h. Electrolyte concentrations and LDH activity significantly increased in serum samples beyond 48 h. Bicarbonate should not be performed as add-on test at all.


The presented data indicate that the conditions within an SRM have no clinical impact on sample stability and allow stable measurement of routine analytes within 72 h, comparable to manual storage facilities.

Corresponding author: Matthijs Oyaert, Department of Laboratory Medicine, Ghent University Hospital, C. Heymanslaan 10, 90000 Ghent, Belgium, E-mail:

  1. Research funding: None declared.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Competing interests: Authors state no conflict of interest.

  4. Informed consent: No informed consent was needed for this study, but the study was performed according to the Declaration of Helsinki and approved by the local Ethical Committee of Ghent University Hospital (study registration number B6702021000891).

  5. Ethical approval: The local Institutional Review Board deemed the study exempt from review.


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Supplementary Material

The online version of this article offers supplementary material (

Received: 2021-08-03
Accepted: 2021-10-20
Published Online: 2021-11-02
Published in Print: 2022-01-26

© 2021 Walter de Gruyter GmbH, Berlin/Boston

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