Roche Tissue Diagnostics (RTD), USA
Title: Rapid Two-Temperature Formalin Tissue Fixation Reduces Assay Variability for Improved Diagnosis and Therapy
Biography: David Chafin
Precision medicine is based on obtaining diagnostic and therapeutic data from clinical assays for each individual. In tissue diagnostics, non-standradized pre-analytical factors often confound assay results. One such step, Formalin fixation, is a mainstay of modern histopathologic analysis, yet the practice is poorly standardized and a significant potential source of preanalytical errors. Concerns of workflow and turnaround time drive interest in developing shorter fixation protocols, but rapid protocols can lead to poor histomorphology or inadequate downstream assay results. Variable assay results can lead to errors in diagnosis and treatment depending on the specifics of the disease and biomarkers involved. Additionally, assays such as immunohistochemistry for phosphorylated epitopes have historically been challenging in the context of formalin-fixed tissue, indicating that there may be room for improvement in this process that is fundamental to the practice of anatomic pathology. With these issues in mind, we studied basic formalin biochemistry to develop a novel formalin fixation protocol that involves a pre incubation in subambient temperature formalin prior to a brief exposure to heated formalin(1).
This new protocol is more rapid than standard protocols yet preserves histomorphology and yields tissue that is compatible with an expanded set of downstream clinical and research assays. Using this novel protocol we found increased preservation of phosphorylated epitopes on proteins, important protein biomarkers such as FoxP3 and RNA species such as mRNA and miRNA.
1.Chafin, D., Theiss, A., Roberts, E., Borlee, G., Otter, M., and Baird, G. S. (2013) Rapid two-temperature formalin fixation. PLoS One 8, e54138