Abstract

Background: MicroRNAs (miRNAs) are a group of small endogenous, non-coding RNA molecules that have been demonstrated to be essential regulators of many critical biological and pathological processes. Because of their high stability in blood and the strong implication of miRNA expression profiles for human diseases, miRNAs are currently emerging as promising circulating biomarkers for the diagnosis or prognosis of a variety of human diseases. The TRIzol-based technique has been widely used for cell or tissue RNA extraction because of its economy and reliability. However, the original TRIzol-based RNA isolation protocol was not specifically designed for microRNA extraction from serum samples. When it was used to extract serum microRNAs, due to the short sequence and low level of microRNAs, the isolation efficiency in most cases could not meet the requirement. To address this issue, in this study, an improved TRIzol-based protocol was established by modifying the extraction procedure of the original TRIzol-based protocol. The performance of the improved TRIzol-based protocol was evaluated by comparison with other methods.
Methods: Total RNA was isolated by the improved TRIzol-based method, the original method, and two other commonly used methods. RT-qPCR and spectrophotometry were used to examine the quality and yield of total RNA.
Results: The improved method was more efficient than the original protocol and more suitable for real-time PCRbased profiling experiments.
Conclusions: The optimized TRIzol-based method described in this report is suitable for the extraction of serum microRNAs and useful for the development of microRNAs as diagnostic biomarkers.

DOI: 10.7754/Clin.Lab.2015.150604