Forensic DNA Recovery from FFPE Tissue Using the Maxwell® RSC Xcelerate Kit: Optimization, Challenges, and Limitations

Background/Objectives: Obtaining reliable DNA profiles from archival tissue preserved as formalin-fixed, paraffin-embedded (FFPE) samples remains a major challenge in both forensic and medical evaluations. The quality of DNA isolated from FFPE material is frequently compromised due to formalin-induced fragmentation and chemical modifications. These limitations are particularly relevant in cases of suspected medical malpractice related to cancer diagnosis or treatment, where retrospective molecular analyses may provide critical evidence. The aim of this study was to evaluate the performance of the Maxwell® RSC Xcelerate DNA FFPE Kit (Promega) in generating DNA profiles from archival FFPE tissue blocks of endometrial cancer and to identify the limitations associated with this approach. Methods: Archival FFPE blocks of endometrial cancer were analyzed using the Maxwell® RSC Xcelerate DNA FFPE Kit. DNA yield, purity, and degradation indices were assessed using standard real-time PCR-based quantification methods. Short tandem repeat (STR) profiling was performed with forensic genotyping kits, and the completeness, allele balance, and reliability of obtained profiles were evaluated. The obtained results were compared with reference quality thresholds commonly used in forensic practice. Results: The Maxwell® RSC Xcelerate Kit allowed for recovery of relatively high DNA yields with consistently low degradation indices, confirming good extraction efficiency from FFPE samples. Nevertheless, despite favorable quantitative values, the generation of complete STR profiles was often unsuccessful. Partial or incomplete profiles were frequent, characterized by allele dropout and imbalance, which substantially reduced their evidentiary value. These findings suggest that DNA fragmentation and fixation-related artifacts impair amplification efficiency and limit the usefulness of STR analysis. Conclusions: This study emphasizes the persistent challenges of DNA profiling from FFPE tissue in forensic-medical contexts. Although the Maxwell® RSC Xcelerate Kit demonstrated effective DNA recovery, the ability to generate complete and interpretable STR profiles remained limited. Further refinement of extraction protocols, as well as improved interpretative strategies, are required to enhance the reliability and evidentiary significance of molecular analyses based on archival FFPE material.