miRNA Extraction: A Method to Extract miRNA from Plasma Sample

- MicroRNAs, or miRNAs, are small non-coding RNAs involved in gene regulation. Their expressions are altered during cancer, and hence are potential cancer biomarkers. To begin miRNA isolation, take freshly collected whole blood sample and centrifuge at 4 degrees Celsius to separate plasma from blood cells. Transfer the supernatant to a fresh tube and centrifuge again to obtain a clearer plasma supernatant. Extract the supernatant, treat with chilled homogenisation solution, followed by lysis buffer to homogenize the sample. Add proteinase K enzyme solution to degrade proteins, particularly the nucleases that would otherwise digest RNA during downstream steps.

- Next, load the lysate into the designated well of a preassembled instrument specific nucleic acid extractor cartridge. Add DNase 1 solution to the appropriate well to eliminate genomic DNA from the sample. Add nuclease-free water to the elution tube assembled on the cartridge for conditioning before miRNA isolation. Load the cartridge assembly into the nucleic acid extractor. Select and run the appropriate miRNA purification software. When complete, remove the elution tube containing miRNA and store at minus 80 degrees Celsi