FFPE processing has been the cornerstone of clinical pathology for over a century. The workflow involves tissue fixation in 10% neutral buffered formalin (typically 24–48 hours), followed by dehydration through graded alcohols, clearing in xylene, and infiltration with molten paraffin wax.
The resulting paraffin block can be stored indefinitely at room temperature, sectioned at 3–5 μm thickness, and mounted on glass slides for staining. This standardization means that virtually every diagnostic pathology laboratory worldwide uses identical sample preparation–a critical advantage for any technology seeking clinical adoption.
Formalin fixation creates methylene bridges between proteins, crosslinking tissue components and preserving morphological architecture. While this crosslinking can mask some epitopes (requiring antigen retrieval), it also stabilizes protein-protein interactionsLoading... in their native spatial relationships–preserving the very engagement states that functional biomarkersLoading... measure.