INTRODUCTION: The use of cytological specimens in cancer genome medicine has garnered considerable attention, but the long-term quality of nucleic acids from unstained specimens remains unclear. This study aimed to evaluate the quality of nucleic acids extracted from unstained specimens fixed with 95% ethanol or spray fixation over varying durations.
METHODS: Two lung cancer cell lines were prepared using the auto smear method and fixed with 95% ethanol, and spray-fixed specimens were stored for 30 min, 1 day, 3 days, 1 week, 2 weeks, 1 month, 3 months, and 6 months. DNA was extracted using a DNA extraction kit, and quality was assessed using agarose gel electrophoresis and PCR.
RESULTS: Nucleic acids extracted from unstained specimens showed no fragmentation after six months of fixation and were amplifiable by PCR, regardless of the fixation method.
CONCLUSION: Nucleic acids extracted from unstained specimens preserved high quality over six months, suggesting that such specimens are suitable for genetic testing. This finding has significant implications for the long-term storage and clinical application of cytological specimens in cancer genome medicine.
