Degradation of serum microRNAs during transient storage of serum samples at 4℃.
Author(s): Aiso T, Takigami S, Yamaki A, Ohnishi H
Publication: Ann Clin Biochem, 2018, Vol. 55, Page 178-180
PubMed ID: 28372464 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of storing serum for 24 h at 4°C on levels of microRNA (miR)-122, miR-145, and miR-92a in serum and extracellular vesicles.
Conclusion of Paper
Levels of miR-122 and miR-145 declined in serum and extracellular vesicles when stored for 24 h at 4°C but levels of miR-92a were unchanged.
This study investigated the effects of storing serum for 24 h at 4°C on levels of microRNA (miR)-122, miR-145, and miR-92a in serum and extracellular vesicles. Blood was collected from three healthy donors into Vacutainer tubes. Serum was isolated 30 min after blood collection by centrifugation at 1500 x g for 10 min at 4°C. Serum was then stored for 0 or 24 h at 4°C and centrifuged again at 20,000 x g for 10 min at 4°C to remove cellular debris. The resultant serum specimens were pooled and aliquoted. Extracellular vesicles were extracted from serum using the Total Exosome Isolation Reagent. Serum was stored frozen at -80°C until miRNA extraction. MiRNA were extracted from serum and extracellular vesicles using a modification of the miRNeasy Serum/Plasma Kit protocol and reverse transcribed using the TaqMan MicroRNA Reverse Transcription Kit. Levels of miR-92a, miR-122, and miR145 were quantified by real-time RT-PCR and normalized to cel-miR-39 which was added during extraction.
Summary of Findings:
When serum was stored for 24 h at 4°C, levels of miR-122 declined to 35.9% of baseline in serum (P=0.00023) and 52.2% of baseline for extracellular vesicles (P=0.014) and levels of miR-145 declined to 29.3% of baseline in serum (P=0.000047) and 56.5% of baseline for extracellular vesicles (P=0.0059). In contrast, levels of miR-92a in serum and extracellular vesicles were unaffected by storage of serum at 4°C for 24 h. The authors report a significant reduction in miR-145 in serum after just 6 h of storage but do not indicate if similar changes in miR-122 occur.
Analyte Technology Platform RNA Real-time qRT-PCR
Classification Pre-analytical Factor Value(s) Storage Storage duration 0 h
Real-time qRT-PCR Specific Targeted nucleic acid miR-92a