Abstract
INTRODUCTION: Thymic epithelial tumours (TET) are a rare, histologically varied group of malignancies, classified by the World Health Organization into 5 subtypes ranging from indolent to aggressive forms. Formalin-fixed paraffin-embedded (FFPE) tissues represent the conventional approach for preserving TET tissues in pathology archives, ensuring long-term stability. Advancements in molecular techniques have significantly improved the molecular analysis in TET. Their efficacy is dependent upon the extraction of high-quality DNA from FFPE samples. The formalin-fixed paraffin-embedded preservation method and extended storage duration, however, pose challenges for molecular analysis because of DNA crosslinking, fragmentation, and reduced recovery efficiency and purity. MATERIAL AND METHODS: This investigation evaluated the performance of 3 commercial DNA extraction kits: the QIAamp® DNA FFPE Tissue Kit, the GeneJET® FFPE DNA Purification Kit, and the MasterPure™ Complete DNA and RNA Purification Kit, across 20 FFPE and 3 fresh TET samples, representing various sexes, ages, histological subtypes, and preservation conditions. The evaluation of DNA yield, purity, and compatibility for subsequent applications was conducted for each method. RESULTS: The QIAamp kit produced the most substantial and reliable DNA yields of 1785.5 ng (Qubit) and 3280 ng (NanoDrop), along with a high level of purity. The DNA has been determined to be appropriate for polymerase chain reaction, Sanger sequencing, and whole genome sequencing regarding its quality and quantity. CONCLUSIONS: The QIAamp kit demonstrates superior performance compared to the others, providing high- quality DNA that is suitable for all molecular applications across all TET subtypes and sample conditions.