Part one of three
Formalin Fixed Paraffin Embedded samples (FFPE) have been a mainstay of the pathology lab for over 100 years. Initially FFPE blocks were sectioned, stained with simple dyes and used for studying morphology, but now a variety of biomolecules can be analyzed in these samples. Over the past 10 years we have discovered that there is a treasure trove of genomics data waiting to be unearthed in FFPE tissue. While viral RNAs and miRNA were some of the first molecules found to be present and accessible for analysis starting in the 1990s, improvements to DNA and RNA extraction methods have demonstrated that PCR, qPCR, SNP genotyping, Exome and WGS are possible. This has resulted scientific publications of DNA and RNA data generated from FFPE samples starting in 2006, and today we see immense amounts of data generated from FFPE—with nearly 2000 citations in 2018 reporting sequencing of FFPE samples.
Depending on the type of project, prospective or retrospective, the genomics scientist has an opportunity to affect the probability of success by better understanding the fixation process. The challenge with FFPE is the host of variables that have the potential to negatively affect downstream assays.Continue reading “Nucleic Acid from FFPE Samples: Effects of Pre-Analytical Factors on Downstream Success”