Neves Cardoso, Paula LilianaSerra, ArmandoBogas, VanessaBalsa, FilipaLopes, VirginiaDario, RitaPorto, Maria JoãoAmorim, AntónioCorte Real, FranciscoBrito, Pedro2026-01-222026-01-222025-05Cardoso, P., Serra, A., Bogas, V., Balsa, F., Lopes, V., Dario, R., Porto, M. J., Amorim, A., Corte Real, F., & Brito, P. (2025). Internal Validation of the Investigator 26Plex QS Amplification Kit: a high-throughput multiplex assay for reference and low copy number DNA samples. In . J. M. Butler, A. Carracedo, M. V. Lareu, A. Freire-Aradas, A. Mosquera-Miguel, C. Phillips, & M. de la Puente (Eds.) 30th Congress of the International Society for Forensic Genetics: Proceedings. (2nd rev. and corrected ed., pp. 1051–1059). Universidade de Santiago de Compostela. https://doi.org/10.15304/cc.2025.1869http://hdl.handle.net/10400.26/61121Human singularity provides a foundation for forensic genetics, where the study of Short Tandem Repeats (STRs) is key. Furthermore, the development of polymerase chain reaction (PCR) has revolutionized the field by enabling the amplification of specific DNA markers. The Investigator® 26plex QS Amplification Kit is a highly robust multiplex PCR system, for human identification. In this study, we report the results obtained from the internal validation carried out at the Portuguese National Institute of Legal Medicine and Forensic Sciences. The results showed that the Investigator® 26plex QS kit proved to be a robust tool for the analysis of forensic samples, offering high sensitivity and specificity.engValidationAmplification KitThresholdsSTRsresearch articlehttps://dx.doi.org/10.15304/cc.2025.1869