DNA extraction from FTA paper
DNA isolated from formalin-fixed paraffin-embedded (FFPE) tissue is usually more degraded and contains more polymerase chain reaction (PCR) inhibitors than DNA isolated from nonfixed tissue.
In addition, the tumor size and cellular heterogeneity found in tissue sections can often impact testing for molecular biomarkers.
As a potential remedy to this situation, one has evaluated the use of Whatman FTA paper cards for collection of colorectal tumor samples before tissue fixation and for isolation of DNA for use in a real-time PCR-based KRAS mutation assay.
Whatman FTA paper cards for collection of colorectal tumor samples before tissue fixation and for isolation of DNA have many advantages including ease of use, intrinsic antimicrobial properties, long storage potential (stability of DNA over time), and a faster turnaround time for results.
Extracted DNA should be suitable for most molecular diagnostic assays that use PCR techniques.
This novel means of DNA preservation from surgical specimens would benefit from additional study and validation as a dependable and practical technique to preserve specimens for molecular testing.
References
KRAS Detection in Colonic Tumors by DNA Extraction From FTA Paper: The Molecular Touch-Prep. Petras ML, Lefferts JA, Ward BP, Suriawinata AA, Tsongalis GJ. Diagn Mol Pathol. 2011 Dec;20(4):189-93. PMID: #22089345#