FFPE Tumor Tissue Macrodissection: A Technique to Obtain Specific Tumorous Tissue from Unstained Specimens

To begin macrodissection, take a glass slide carrying a tissue specimen. Additionally, take a reference slide carrying the same tissue specimen and stain it using hematoxylin and eosin for H&E stain.

In normal cells, hematoxylin imparts a blue stain to nucleic acids, while the eosin counterstain shows the cellular proteins pink. The deep blue coloration of the nucleus helps in differentiating cancer cells from normal cells.

Overlay the H&E stained slide with the unstained slide to align the tissue specimens. Locate the portion containing tumor cells on the H&E stained slide. Mark the corresponding area on the unstained slide.

Scrape off the desired tissue from the unstained slide. Using a wet pipette tip, collect the scraped tissue to ensure an easy transfer of the tissue specimen. Transfer the tissue into a tube containing a lysis buffer. Components of the lysis buffer digest the tissue, releasing the constituents of the cell.

Treat the lysate with a suitable protease and incubate at a high temperature. The protease cleaves the contaminating DNases, thereby protecting the DNA from degradation. Store the DNA containing tissue lysate for downstream analysis.