Sample Preparation Guidelines for RNA Assays

For the best results 0.1–0.5 ng of total RNA should be loaded in a volume of 25 µL per sample well, or to the digest step add 40 µL of plasma or serum.

Methods for RNA Isolation

Total RNA isolated from cells and tissues: For optimal results, any of the methods given for the FirePlex miRNA assay can be used.

Total RNA isolated from plasma or serum: For optimal results, total RNA should be isolated using the TRIzol-LS® standard protocol with 250 µL of sample and the addition of 1 µL 15 mg/mL GlycoBlue™ before precipitation. Following isopropanol-induced precipitation the pellet should be washed with 75% ethanol then, following drying, the sample should be resuspended in 50 µL water free from RNase. It is suggested that sample-equivalents of 40 µL are ran, i.e. 8 µL of the 50 µL + 17 µL RNase-free water = 25 µL sample for assay.

Plasma or serum samples: For optimal results, the sample should be stored frozen at -80 °C with the number of freeze/thaws the sample undergoes as low as possible. Methods given for the FirePlex miRNA assay can be used.

Important Notes

When running any RNA isolations that use a column, care must be taken that the method does not have negative bias towards small RNAs. Recommendations regarding ethanol washing and rinsing procedures should be adhered to so that miRNAs are not excluded from the final pellet.

For all isolation methods, it is important that the RNA is resuspended in water that is RNase free, or 1X TE, to keep salt levels low.

Quantifying the RNA in samples like 250 µL of serum or plasma cannot be achieved using absorbance technologies such as Nanodrop, and may also be unreliable using more sensitive systems such as Promega Quantus.

Accurate miRNA profiling can be carried out on samples, regardless of if they have been quantified, using the FirePlex miRNA Assay.

About Abcam

Abcam is a global life sciences company providing highly validated antibodies and other binders and assays to the research and clinical communities to help advance the understanding of biology and causes of disease.

Abcam’s mission is to serve life scientists to help them achieve their mission faster by listening to their needs, continuously innovating and improving and by giving them the tools, data and experience they want. Abcam’s ambition is to become the most influential life science company for researchers worldwide.

Sponsored Content Policy: publishes articles and related content that may be derived from sources where we have existing commercial relationships, provided such content adds value to the core editorial ethos of News-Medical.Net which is to educate and inform site visitors interested in medical research, science, medical devices and treatments.

Last updated: Mar 8, 2023 at 12:32 AM


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Abcam. (2023, March 08). Sample Preparation Guidelines for RNA Assays. News-Medical. Retrieved on March 01, 2024 from

  • MLA

    Abcam. "Sample Preparation Guidelines for RNA Assays". News-Medical. 01 March 2024. <>.

  • Chicago

    Abcam. "Sample Preparation Guidelines for RNA Assays". News-Medical. (accessed March 01, 2024).

  • Harvard

    Abcam. 2023. Sample Preparation Guidelines for RNA Assays. News-Medical, viewed 01 March 2024,

Other White Papers by this Supplier