Related Experiment Video
Updated: Jan 17, 2026
Author Spotlight: Obtaining High-Quality CSF and Blood Samples for Epilepsy Biomarker Discovery
Published on: September 1, 2023
Standardization of preclinical methodologies for discovery and validation of circulating microRNA biomarkers for
Noora Puhakka1, Mette Heiskanen1, Xavier Ekolle Ndode-Ekane1
1A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, Kuopio FI-70211, Finland.
Objective:
To analyze the success of harmonization and standardization of plasma miRNA biomarker discovery and validation for post-traumatic epilepsy (PTE) in the EpiBioS4Rx international multicenter project.
Methods:
Adult male Sprague-Dawley rats were randomized to lateral fluid-percussion-induced traumatic brain injury (TBI) or sham operation at three study sites (Finland, Australia, USA). Video-electroencephalogram (vEEG) was performed in the 7th post-injury month to detect spontaneous seizures. Tail vein plasma was collected at baseline and 48 h after TBI for microRNA (miRNA) analysis. Common data elements were generated to document and monitor pre-analytic activities, including housing conditions, post-injury care, blood sampling, plasma preparation, plasma quality, storage, and shipping. miRNA analysis was performed using droplet digital PCR (ddPCR) at one study site (Finland) with on-site standardized procedures.
Results:
The 2-day miRNA levels were successfully measured in 85 % (209/245) of the rats included in the final analysis cohort. Exclusions were related to small sample volume, hemolysis, and failed RNA extraction for ddPCR. Most of the pre-analytical factors leading to sample exclusions were related to non-optimal plasma pipetting. We also recognized gaps in data entry and monitoring of personnel training.
Conclusions:
Our study demonstrates that conducting a successful plasma miRNA biomarker analysis requires procedural harmonization between laboratories, protocol standardization, inclusion and analysis of quality controls, training of researchers, and continuous monitoring of adherence to pre-agreed protocols.
