Researchers extract RNA and DNA from biological samples as a starting point for various downstream biomolecular applications, such as next-generation sequencing, PCR, and microarray analysis. The general steps for nucleic acid extraction involve lysing cells, inactivating nucleases, and purifying the nucleic acid sample from leftover cell debris. Among the most important considerations for performing reliable RNA and DNA extraction are the final sample’s purity and yield, as these variables greatly affect downstream workflows.1 Isolating RNA and DNA from fresh tissue, cell samples, and agarose gels is relatively straightforward and efficient. However, isolating nucleic acids from formalin-fixed, paraffin-embedded (FFPE) tissue samples is no easy task, given the chemical damage that tissue-preserving formaldehyde imparts.2

          Conceptual image of nucleic acid extraction from a formalin-fixed, paraffin-embedded tissue sample, with the tissue shown in the background and a magnifying glass with colored bands of nucleic acid in the foreground.
Extracting higher quality and higher yields of RNA and DNA from formalin-fixed, paraffin-embedded tissue samples allows researchers to maximize biobanked materials for a wide variety of applications.
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FFPE tissue samples allow scientists to glean useful information from the architecture of preserved cells and tissues, but formaldehyde preservation crosslinks proteins and nucleic acids and disrupts nucleotide sequences.3,4 As a result, the quality and yield of RNA and DNA from FFPE samples is often poor, which limits downstream applications that require sufficient starting material. There are significant benefits to extracting adequate quality and yields of nucleic acids from FFPE samples. For example, taking advantage of biobanked archival materials such as tissue biopsies expands the scope of basic cancer and immunology research, medical diagnostics, therapeutics development, and retrospective and prospective clinical studies.

Researchers using standard extraction protocols that heat samples to eliminate formaldehyde-induced crosslinks face poor yields and nucleic acid quality and therefore seek new technologies that enable RNA and DNA extraction from FFPE samples. For example, Biotium’s RNAstorm™ and DNAstorm™ kits enable yields of more amplifiable RNA and DNA from FFPE tissue samples, compared to other methods. These kits use catalytic CAT5™ technology, which allows researchers to more efficiently remove formaldehyde crosslinks under gentler conditions, generating more amplifiable DNA and RNA for downstream applications.

Learn more about Biotium's unique RNAstorm™ and DNAstorm™ FFPE Extraction Kits.

References

  1. Tan SC, Yiap BC. J Biomed Biotechnol. 2009;2009:574398 
  2. Srinivasan M, et al. Am J Pathol. 2002;161(6):1961-71
  3. Williams C, et al. Am J Pathol. 1999;155(5):1467-71 
  4. Do H, Dobrovic A. Clin Chem. 2015;61(1):64-71
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