Typing of 24 mtDNA SNPs in a Chinese Population Using SNaPshot Minisequencing / 华中科技大学学报（医学）（英德文版）

Three SNaPshot multiplex assays were developed to test 23 coding region single nucleo-tide polymorphisms (SNPs) and one control region SNP outside hypervariable regions (HVR) Ⅰ and Ⅱ, which was aimed at increasing the discrimination power of the mitochondrial DNA (mtDNA) typing in forensic casework, and confirming haplogroup assignments of mtDNA profiles in both hu-man population studies and medical research. The selected SNPs targeted the East Asian phylogeny. These multiplex assays were validated by comparing with the sequencing analysis of samples chosen randomly. The mtDNA variations of 100 unrelated individuals from the Wuhan population in China were examined and classified into 3 i haplotypes, and the haplotype diversity was estimated to be 0.952. The multiplex SNaPshot method is rapid and robust, and suitable for large-scale screening studies of mtDNA variability.

Spectrophotometric Determination of Trimethylamine-nitrogen in Cadaver Tissues for the Estimation of Late Postmortem Interval: A Pilot Study / 华中科技大学学报（医学）（英德文版）

To study the relationship between the late postmortem interval (PMI) and trimethylamine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMD by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance (A value) and TMA-N at the concentration of 1-10 mg/L (R2 =0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7 d since death, the best correlation between PMI and TMA-N concentration was found in muscles.With PMI as an independent variable, the cubic polynomial regression equation was y= --0.457x3+6.519x2-24.574x+27.207 (R2=0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2+55.727x-95.819 (R2=0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.