Methods for RNA Extraction

Types of RNA used for research include total RNA, mRNA, sequence-specific RNA, microRNA, and viral RNA. Researchers requiring testing of more than RNA from samples can opt to use RNA/DNA or RNA/protein kits.

There are several types of RNA that play distinct roles within the cell. mRNA carries the genetic information from DNA to the ribosomes where it is translated into proteins. Transfer RNA (tRNA) helps in the translation process by bringing amino acids to the ribosomes. Ribosomal RNA (rRNA) is a major component of ribosomes, the cellular machinery responsible for protein synthesis. There are small nuclear RNA (snRNA) and small nucleolar RNA (snoRNA) involved in various RNA processing and modification events.

Learn more about RNA sequencing methods

RNA extraction kits can further get categorized based on the type of RNA extraction method it utilizes. Types of RNA extraction methods include sequence-specific RNA purification, miRNA and small RNA isolation, viral RNA extraction, and total nucleic acid/protein purification.

Sequence-specific RNA extraction is a method used to selectively isolate target segments of RNA molecules. Sequence-specific RNA include low-abundance cDNA from libraries, mutated sequences, infectious agents, and microsatellites. Target a specific RNA sequence and isolate only those RNA molecules directly from crude lysates or other biological fluids using magnetic bead technology. Dynabeads Streptavidin magnetic beads can work for numerous applications, including protein purification, nucleic acid purification, protein interaction studies, immunoprecipitation, immunoassays, phage display, biopanning, drug screening, and cell isolation.

Dynabeads Streptavidin binds to highly specific biotinylated antibodies or ligands.

• Compatible with mass spectrometry (MS)
• Low non-specific binding
• For samples high in soluble IgGs
• Recombinant Ab lacking the Fc region

Learn more: Sample preparation for RNA seq 
Learn more: How to capture biotinylated molecules
Learn more: Nucleic acid capture assays

• Brochure: Dynabeads streptavidin products for manual and automated protocols
• Application note: Mutation detection sensitivity in matched FFPE tissue and liquid biopsy samples
• Dynabeads M-270 Streptavidin protocol

MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) help modulate gene expression. Along with several other classes of small noncoding RNAs (e.g., snRNA, snoRNA, and piRNA), they have tremendous impact on a variety of biological processes.

While most traditional RNA isolation methods are not very efficient at recovering these smaller RNAs, several kits developed by our RNA experts offer quantitative recovery of small RNAs from a variety of sample types.

Which microRNA and small RNA isolation kit is right for you?

Learn more: Getting started with microRNA research
Learn more: Got small RNA?

The extraction of viral RNA differs from cultured cells or tissue samples as it focuses specifically on isolating RNA from the viral particles rather than the host cells. This requires additional steps to separate and release the viral particles from the sample matrix. Additionally, the viral RNA extraction process may involve more stringent measures to help prevent contamination and enable the purity of the viral RNA for downstream analysis.

Viral RNA extraction kit selection guide

Explore: MagMAX magnetic bead kits for viral RNA extraction
Explore: PureLink viral RNA extraction kits

Research sometimes requires testing of more than just RNA from each sample. For example, researchers may want to compare the effects of genetic variations on gene expression, or to evaluate both protein and cognate mRNA levels. To help serve this need, some purification products are designed to extract both RNA and DNA, or both RNA and protein from samples. Total nucleic acid extraction kits with these capabilities allow users to get more out of their samples while employing one kit to streamline the process.