The Impact of Tube Type, Centrifugation Conditions, and Hemolysis on Plasma Circulating MicroRNAs.

Background: In recent years, liquid biopsy has emerged as a promising tool for the diagnosis and prognosis of numerous diseases, including cancer. Among the biomolecules analyzed in liquid biopsies are plasma circulating microRNAs (miRNAs), small non-coding RNAs that have proven to be crucial in the regulation of gene expression and the pathobiology of different health conditions, making them useful as biomarkers. However, variations in preanalytical conditions during biospecimen collection and processing can affect the analytical results.

Objectives: Herein, we determined how the type of collection tube, the number of centrifugations, and the degree of hemolysis can affect plasma circulating miRNA levels.

Methods: A cohort of 11 healthy donors was included. Whole blood was collected and handled in three different conditions, and miRNAs levels were analyzed using quantitative RT-PCR.

Results: Our results show that the differences in the type of preservative tubes influence hemolysis, measured as OD at 414 nm. Moreover, the number of centrifugations performed also altered miRNAs levels, increasing or decreasing them depending on the miRNA analyzed. Hence, our study shows that alterations in preanalytical conditions affect miRNAs levels, particularly the number of centrifugations and the type of collection tubes.

Conclusions: In our work, we highlight the importance of registering the preanalytical conditions in a standardized way that might be considered when analytical results are obtained.