Abstract

BACKGROUND
The preservation of optimized DNA and its extraction from formalin-fixed, paraffin-embedded (FFPE) tissues are important issues. There has been some doubt over whether 10% neutral-buffered formalin is an ideal fixation solution for DNA preservation over non-buffered formalin, as conventionally recommended. In this study, the correlation between the efficiency of DNA extraction from FFPE tissues and buffered formalin was evaluated.
METHODS
Several tissues with same conditions except fixatives were fixed in four different formalin solution groups and were routinely processed as paraffin-embedding protocols. DNAs were extracted from four different FFPE tissues that were stored for over 3 months and over 9 months. The quantity and quality of the DNAs were assessed with a NanoDrop ND-1000 spectrophotometer, and the polymerase chain reaction (PCR) amplification and degradation were analyzed via microchip electrophoresis. KRAS mutation analysis and microsatellite instability (BAT25) PCR were performed with each sample.
RESULTS
The results showed no remarkable difference in the four groups.
CONCLUSIONS
The study findings demonstrate that DNA preservation is fairly unaffected by a neutral buffer where there is short formalin manufacture period and an adequate formalin fixation time before embedding in paraffin.

• Keywords: Tissue fixation;Formaldehyde;Tissue preservation;Pathology, molecular;DNA degradation;