How does qNPA analyze gene expression in FFPE material without RNA extraction?
In most fixed tissue specimens, the majority of RNA is cross-linked to cellular material, much of which is insoluble and is therefore resistant to RNA extraction. qNPA oligonucleotides can hybridize to these tissue-bound RNAs and the nuclease protection assay can proceed as normal. As the image to the left shows, a significantly larger amount of signal is obtained from the FFPE samples (column A) which include the pellet material in the qNPA process. This is distinctly different from the fresh tissue control (column B), where the material is fresh frozen and RNA is readily soluble in the supernatent. Only qNPA can access the bound RNA in FFPE that RNA extraction techniques cannot recover, providing an advantage over other gene expression techniques.
