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Figure 3 | BMC Biotechnology

Figure 3

From: Comparison of miRNA expression patterns using total RNA extracted from matched samples of formalin-fixed paraffin-embedded (FFPE) cells and snap frozen cells

Figure 3

A schematic representation of the impact of cross-links on RNA extraction. In FFPE materials, RNA has been chemically modified by methylol groups to form cross-links with protein. Digestion with proteinase K [6] followed by column elution is the common method used to extract RNA from FFPE. However, a fraction of RNA remains impervious to extraction because of un-removed cross-links. The longer an RNA molecule is, the more likely cross-links will remain after the digestion procedure. Therefore, it is easier to extract small RNA molecules than larger ones from archival material.

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