Authors: Jared Barrot, Mackenzie Burr, Isaac Packer, Peyton Worley, Delaney Anderson, Jack Davis, Jeffrey Okojie, Ken Dixon
Mentors: Jared Barrott
Insitution: Brigham Young University
In cancer diagnosis, drug testing, and treatment, analysis is done almost exclusively on formalin-fixed paraffin-embedded (FFPE) tissue samples, a process known to cause chemical cross-linking, DNA fragmentation, and degradation. With the push for genetic testing and personalized medicine, cryopreservation of tissue samples has started to gain traction in the research community. We utilized FFPE samples and cryopreserved samples, extracted DNA, and compared the samples using three criteria: DNA purity, quality, and yield. DNA yield, measured on nanograms of DNA to milligrams of tissue basis, demonstrated a five times the yield in cryopreserved samples than in FFPE. DNA purity did not show significant differences between a cryopreserved tissue sample versus a FFPE tissue sample, confirming valid use of FFPE storage methods if purity is the only factor; however, DNA quality was significantly better in cryopreserved tissue samples, with nearly twice the DNA quality number (DQN) than FFPE samples demonstrated, with significant portions of longer base pair DNA fragments present, widening the range of molecular applications of the sample. These cryopreserved tissues provide higher DNA quality, a higher percentage of significantly longer DNA fragments, and increased DNA yield from individual samples, confirming that cryopreservation is a better option than FFPE when it comes to choosing tissue preservation and storage methods. More molecular assays and tests can be run, and smaller samples are necessary when utilizing cryopreservation, proving it to be a better option than the “gold standard” of FFPE, particularly in regards to cancer diagnosis, drug testing, and treatment exploration.