What is RNA?

Ribonucleic acid ( RNA) is a polymeric molecule that is important for the coding, encoding, modulation, and expression of genes in different biological functions. RNA and DNA are both nucleic acids. Nucleic acids, along with lipids, proteins, and carbohydrates, are one of the four main macromolecules that are essential for all known life types. Like DNA, RNA is formed as a sequence of nucleotides, but unlike DNA, RNA is classified in nature as a single-strand folded on itself, rather than a paired double-strand. Cellular organisms use messenger RNA ( mRNA) to convey genetic information (using guanine, uracil, adenine, and cytosine nitrogen bases, denoted by letters G, U, A, and C) that guides the synthesis of specific proteins. Many viruses store their genetic material using the genome of the RNA (University of California, Los Angeles, 2015).

Some RNA molecules play an important role in cells by catalyzing biochemical processes, regulating gene expression, or detecting and transmitting cell signal results. One of these active processes is protein synthesis, a universal mechanism in which RNA molecules guide protein synthesis to ribosomes. This method uses RNA transfer (tRNA) molecules to carry amino acids to the ribosome, where ribosomal RNA (rRNA) then bonds amino acids together to form coded proteins (University of California, Los Angeles, 2015).

RNA purification and isolation?

Ribonucleic acid ( RNA) is an essential aim for a wide variety of experimental analyses. RNA purification is, therefore, a crucial first step in a series of preparation and analytical methods, especially in the detection of thousands of infectious, bacterial, and parasitic diseases, in the diagnosis of genetic disorders and tumours, as well as in basic science. To have appropriate and accurate data, molecular biology techniques used for these purposes involve pure and intact mole of purified RNA. In addition, RNA must be purified efficiently and reproducibly from different heterogeneous substances, such as fresh or frozen tissues, cell lines, PCR products or long-term chemically stored materials (Vanickova, 2009).


Methods of RNA purification

Mainly, RNA purification methods can be classified into three classes. These classes are discussed below:

  • The first group of approaches is focused on the extraction of organic phenol: chloroform. 
  • The second group involves procedures of RNA purification through its potential to adhere to particular structures in the existence of chaotropic salt.
  • The third group includes methods of RNA separation on isopycnic gradients. While RNA can be isolated from either prokaryotic or eukaryotic species, this analysis is intended to provide a general overview of available eukaryotic, mammalian, tissue procedures (Vanickova, 2009).

Promega’s new SV Total RNA Isolation System 

Promega’s new SV Total RNA Isolation System provides a total method for the insulation of RNA quality from small quantities of starting material. This method offers a short and convenient methodology for the production of processed and intact complete RNA from tissues, cultured cells and whole blood samples. This purification is accomplished without the utilization of phenol/chloroform extracts and uses a basic DNase step to effectively remove genomic DNA. No genomic DNA pollution is detected when the RNA is analyzed by reverse transcription-PCR (Brisco, 1997). 

The SV Total RNA Isolation Device method delivers top-quality total RNA after a sole round of purification without organic extraction or precipitation. The technique is simple to conduct with small amounts of tissue, cultured cells, or with a sample of blood and can be used to treat several samples at the same time. Unlike other similar, commercially available devices, the Promega columns do not clog during centrifugation. Overall, RNA yields are greater, genomic DNA contamination is not present in RT-PCR analysis, and the outcomes are more reliable as seen by a lower % CV. The protocol is simple to execute and can be done in as early as an hour. (Brisco, 1997).


Brisco, P. (1997). RNA Purification: A Rapid and Versatile Protocol for the Isolation of Total RNA. https://www.researchgate.net/publication/280796614_RNA_Purification_A_Rapid_and_Versatile_Protocol_for_the_Isolation_of_Total_RNA

University of California, Los Angeles. (2015). Nucleotides and Nucleic Acids. Wayback Machine. https://web.archive.org/web/20150923202511/http://www.chem.ucla.edu/harding/notes/notes_14C_nucacids.pdf

Vanickova, Z. (2009). Methods of RNA Purification. All Ways (Should) Lead to Rome. PubMed. https://www.researchgate.net/publication/41465321_Methods_of_RNA_Purification_All_Ways_Should_Lead_to_Rome