DNA amplifiability after xylene-free tissue processing: supporting precision medicine without molecular compromise
DESCRIPTION
Elena Carlessi1, Daria Gafforelli1, Erika Lenzi1, Sara Bassani1, Alessia Poli1, Laura Cavalleri1, Carmelo Lupo1,2,
1Innovation Department, Diapath StatLab Company
2Department of Engineering and Applied Sciences, University of Bergamo, Italy
Abstract
In modern diagnostic pathology, a single formalin-fixed, paraffin-embedded (FFPE) tissue block is increasingly required to support multiple analytical approaches, including morphological assessment, immunohistochemical biomarker profiling and molecular testing. The simultaneous preservation of tissue morphology, protein antigenicity and nucleic-acid integrity is therefore essential to ensure reliable diagnostic results and the accurate identification of prognostic and predictive biomarkers that guide personalized therapeutic decisions. Because pre-analytical tissue processing affects nucleic-acid integrity, it directly influences the reliability of downstream molecular pathology.
This white paper reviews the evidence on DNA integrity, amplifiability and antigen preservation in FFPE tissue processed with the Donatello tissue processor and Ottix reagents.
In an independent validation at the University of Siena, Donatello-processed tissue yielded all four PCR amplicons (100–400 bp), including those at 300 and 400 bp.
In the Diapath internal validation, all 34 DNA extracts tested by real-time PCR were classified as HIGH quality, with QC scores below the 0.04 optimal-range threshold. Genomic DNA ScreenTape showed size-resolved profiles extending beyond 300 bp (DIN 4.8–6.6), and DV200 values of 60.30–86.76% indicated preserved RNA integrity. In an independent matched comparison of three tissue processors at the University of Porto, Donatello produced the fewest processing artifacts on hematoxylin-eosin slides (17.8%, versus 38.4% and 50.7%) and best preserved PD-L1 staining intensity.
Together, these data demonstrate functional DNA amplifiability at and above 300 bp after Donatello processing, supported by orthogonal measures of DNA size distribution, RNA quality and tissue antigenicity.
