TY - JOUR AB - The analysis of complex DNA mixtures is challenging for forensic DNA testing. Accurate and sensitive methods for profiling these samples are urgently required. In this study, we developed 11 groups of mixed male DNA samples (n=297) with scientific validation of D‑value [>95% of D‑values ≤0.1 with average peak height (APH) of the active alleles ≤2,500 rfu]. A strong linear correlation was detected between the peak height (PH) and peak area (PA) in the curve fit using the least squares method (P<2e-16). The Kruskal-Wallis rank-sum test revealed significant differences in the heterozygote balance ratio (Hb) at 16 short tandem repeat (STR) loci (P=0.0063) and 9 mixed gradients (P=0.02257). Locally weighted regression fitting of APH and Hb (inflection point at APH = 1,250 rfu) showed 92.74% of Hb >0.6 with the APH ≥1,250. The variation of Hb distribution in the different STR loci suggested the different forensic efficiencies of these loci. Allelic drop-out (ADO) correlated with the APH and mixed gradient. All ADOs had an APH of <1,000 rfu, and the number of ADO increased when the APH of mixed DNA profiles gradually decreased. These results strongly suggest that calibration parameters should be introduced to correct the deviation in the APH at each STR locus during the analysis of mixed DNA samples. AD - Hebei Key Laboratory of Forensic Medicine, Department of Forensic Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China Institute of Statistics, Renmin University of China, Beijing 100872, P.R. China DNA Laboratory, Forensic Science Service of Beijing Public Security Bureau, Beijing 100085, P.R. China AU - Hu,Na AU - Cong,Bin AU - Gao,Tao AU - Hu,Rong AU - Chen,Yi AU - Tang,Hui AU - Xue,Luyan AU - Li,Shujin AU - Ma,Chunling DA - 2014/07/01 DO - 10.3892/ijmm.2014.1779 EP - 52 IS - 1 JO - Int J Mol Med KW - forensic genetics short tandem repeats male-male mixed DNA average peak height/area of the active alleles heterozygote balance ratio mixture proportion allelic drop-out PY - 2014 SN - 1107-3756 1791-244X SP - 43 ST - Evaluation of parameters in mixed male DNA profiles for the Identifiler® multiplex system T2 - International Journal of Molecular Medicine TI - Evaluation of parameters in mixed male DNA profiles for the Identifiler® multiplex system UR - https://doi.org/10.3892/ijmm.2014.1779 VL - 34 ER -