Source identification of human biological materials in crime scene plays an important role in reconstructing the crime process. Searching specific genetic markers to identify the source of different human biological materials is the emphasis and difficulty of the research work of legal medical experts in recent years. This paper reviews the genetic markers which are used for identifying the source of human biological materials and studied widely, such as DNA methylation, mRNA, microRNA, microflora and protein, etc. By comparing the principles and methods of source identification of human biological materials using different kinds of genetic markers, different source of human biological material owns suitable marker types and can be identified by detecting single genetic marker or combined multiple genetic markers. Though there is no uniform standard and method for identifying the source of human biological materials in forensic laboratories at present, the research and development of a series of mature and reliable methods for distinguishing different human biological materials play the role as forensic evi-dence which will be the future development direction.

Objective To investigate the population genetic polymorphisms of 24 Y-STR loci in unrelat-ed individuals in Eastern Chinese Han population, and to compare the difference of Han group between Eastern China and Guangdong.Methods The population genetics of 24 Y-STR loci in 268 unrelated Han individuals from Eastern China were analyzed by GFS 24 Y-STR amplification kit. The allele fre-quencies in Eastern Chinese Han population were compared with the data in Guangdong Han population, and the difference analysis between two groups was performed.Results Among the 24 Y-STR loci of 268 unrelated Han individuals from Eastern China, 235 alleles and 267 haplotypes were observed. GD value ranged from 0.5649 to 0.9668. The difference between 12 loci(DYS622,DYS552,DYS443etal.) of Han population in Eastern China and in Guangdong was statistically significance.Conclusion GFS 24Y STR amplification system shows favorable polymorphisms, which can be used in patrilineal genetic relationship identification.

Objective To establish a novel multiplex amplification system which comprises 24 Y-STR loci.Methods Total 24 Y-STR gene loci, concluding DYS531,DYS630,DYS622,DYS552,DYS510, DYS449, DYS459a/b, DYS446, DYS443, DYS635, DYS587, DYS527a/b, DYS460, Y-GATA-A10, DYS520, DYS557,DYS522,DYS481,DYS570,DYS385a/b,DYS444, were chosen for establishing the fluorescence multiplex amplification system. The specificity, identity, sensitivity, balance of the amplification, anti-in-terference and accuracy of the system were detected and the gene diversity was investigated in the popu-lation of Guangdong.Results No band was found in nonhuman and female samples that were tested by the established multiplex amplification system. The same genotyping results were obtained from different tissues of the same person. Complete profiles could be obtained from more than 0.1 ng of the standard sample 9948. The loss of alleles was found when the common inhibitors such as hemoglobin and calci-um ion were added 120-200μmol/L and 1.5-2.0 mmol/L respectively to the system which with a strong anti-interference to the indigo, humic acid and EDTA. The typing of 24 Y-STR system could give the reliable results when 146 unrelated male individuals were detected and compared with the Yfiler system parallelly. The haplotype diversity(HD)of the population in Guangdong reached 0.99972 that was better than the result retained from Yfiler system, which the HD was 0.99858.Conclusion The fluorescence amplification system with 24 Y-STR loci established in present study has a wildly application prospect and can be used for cases inspection, paternity tests and Y-STR database construction.

There is an increasing interest in single nucleotide polymorphism (SNP) typing in the forensic field.SNPs are very useful for deftning Y chromosome or mtDNA haplotypes and DNA phenotyping.We focus on comparative advantages of SNP typing over length variations and expected number of loci required to gain probabilities equal to sTR loci in use.This review also offers to the reader a state of the art of SNP genotyping technologies with the advantages and disadvantages of the different techniques and platforms for different forensic requirements.

Matrix-assisted laser desorption/ionization tim e-of-flight im aging m ass spectrom etry (MALDI-TOF-IMS ) has been a classical technique for studying proteom ics in present and a tool for analyzing the distribution of proteins and sm all m olecules w ithin biological tissue sections. MALDI-TOF-IMS can analyze m ultiple unknow n com pounds in biological tissue sections sim ultaneously through a single m ea-surem ent w hich can obtain m olecule im aging of the tissue w hile m aintaining the integrity of cellular and m olecules in tissue. In recent years, im aging m ass spectrom etry technique develops relatively quickly in all biom edical dom ain. T his paper based on the relevant data and review s the present developing level of MALDI-TOF-IMS, the principle of im aging m ass spectrom etry, m ethology and the prospect in foren-sic pathology.

Objective To com pare the concentration of teeth DNA extracted by three different pretreatm ent m ethods and to explore a sim ple, econom ical and practical pretreatm ent m ethod w ith high concentration of extracted DNA from teeth. Methods A total num ber of 21 m olars w ere collected from 7 corpses. The pretreatm ent of 3 m olars from each individual w as random ly perform ed by tooth crum b m ethod, ball-m illing m ethod and liquid nitrogen m illing m ethod and 50 m g tooth crum b w as w eight and DNA w as extracted by A utoM ate ExpressTM forensic DNA extraction system . Subsequently, the concentration of DNA and corresponding STR genotyping of three m ethods w ere com pared. Results The DNA concentration extracted by tooth crum b m ethod, ball-m illing m ethod and liquid nitrogen m illing m ethod w as 0.055 6-1.989 1 ng/μL , 0.036 6-1.175 6 ng/μL and 0.037 8-1.249 0 ng/μL , respectively. The DNA concentration ob-tained by tooth crum b m ethod w as higher (P<0.05) and the success rate of STR genotyping w as high. Conclusion C om bined w ith A utoM ate ExpressTM forensic DNA extraction system , tooth crum b m ethod is an efficient and feasible m ethod to extract DNA from teeth, w hich can be applied in forensic practice.

Objective To determ ine the norm al reference values of 33 elem ents, Ag, Al, As, Au, B , B a, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, G a, H g, Li, Mg, Mn, Mo, N i, Pb, Rb, Sb, Se, Sr, Th, Ti, Tl, U , V , Zn and Zr, in the blood and urine sam ples from the general population in Sanm en County of Zhejiang province, a typical coastal area of eastern China. Methods The 33 elem ents in 272 blood and 300 urine sam ples w ere determ ined by inductively coupled plasm a-m ass spectrom etry (ICP-MS ). The norm ality test of data w as conducted using SPSS 17.0 Statistics.The data w as com pared w ith other reports. Results The norm al reference values of the 33 elem ents in the blood and urine sam ples from the general population in Sanm en County w ere obtained, w hich of som e elem ents w ere found to be sim ilar w ith other reports, such as Co, Cu, Mn and Sr, w hile As, Cd, H g and Pb w ere generally found to be higher than those previously reported. There w as a w ide variation betw een the reports from different countries in blood B a. Conclusion The norm al reference values of the 33 elem ents in the blood and urine sam ples from the general population in Sanm en County are established, and successfully applied to tw o poisoning cases.

Objective To establish the rapid PCR am plification program and system and to verify the technical indexes. Methods PCR m ultiplex and capillary electrophoresis detection of 24 autosom al STR loci and one Y-STR loci using the 6-color fluorescence m arking technology, as w ell as Amelogenin and Y-InDel. Meanw hile, sensitivity, specificity, identity, stability, m ixing and a batch of sam ple tests w ere investigated, and the genotype of various routine sam ples and degraded, exfoliated cell sam ples w ere observed. Results The sensitivity of the system w as 0.062 5 ng. In addition, the genotype could be detected accu-rately only around 65 m in via rapid am plification. The species-specificity w as high and the genotyping of all kinds of dry blood specim ens of filter paper and m ixed, degraded, exfoliated cell sam ples w ere accu-rate. Conclusion The rapid am plification system can significantly im prove the detection rate, and obtain accurate and stable genotyping results, w hich m ay be im portant im plications for the establishm ent of STR database and study on population genetics and forensic identification.

Objective To explore the change rules of peak area ratio of STR loci to Amelogenin (AMEL) locus (STR/A M EL ), a sex-determ ining gene in DNA degradation, and to evaluate the application of STR/A MEL value in the estim ation of DNA degradation degree. Methods DNA w as extracted from iliopsoas, and the variations of STR/A MEL value (Penta E/AMEL, Penta D/AMEL, FGA/AMEL) w ere analyzed after the artificial degradation w as m ade by DNaseⅠ, and the changes of these three ratios of the iliopsoas naturally degraded in an outdoor environm ent w ere also analyzed. The regression curves w ere analyzed using the periods of DNA degradation and outside the body as the independent variable (x) and the STR/A MEL value as the dependent variable (y) and three curve equations under tw o conditions w ere established. Results B oth under the conditions of artificial and natural degradation, STR/A MEL value had a negative relationship w ith the degradation tim e. The relationship betw een STR/A MEL and degradation tim e can be w ell sim ulated by the cubic function. R2 w as over 0.99 under controlled degradation condition and over 0.86 under natural degradation condition. Conclusion The STR/A MEL value (Penta E/AMEL, Penta D/AMEL , FGA/AMEL ) is negatively related w ith the DNA degradation degree, w hich follow s m athem atical regression m odels strictly, and it m ight be applied to evaluate the DNA degradation degree.

Objective To establish regression m odel betw een craniofacial lines and body height by m ea-suring craniofacial lines in Southw est H an m ales using C Tand to accum ulate data for the study of foren-sic anthropology. Methods H ead C Tdata of 273 H an m ales in Southw est w ere collected and 7 cranio-facial lines w ere determ ined. M ultiplanar reconstruction and volum e rendering w ere perform ed by im age post-processing softw are and the selected lines w ere m easured. The relationship betw een each m easuring indicator and body height w as analyzed using SPSS 21.0 softw are. The regression equation of body height estim ation w as established and 50 sam ples w ere selected again and put into the m athem atics m odels to verify its accuracy. Results The linear regression equations of 7 lines w ere established (P<0.05). The correlation coefficients of the unary linear regression equations w ere 0.190-0.439 and the standard errors of the estim ate (SEE) w ere 4.597-5.023 cm . The correlation coefficients of the m ultiple linear regression equation w ere 0.494-0.524 and the SEEw ere 4.418-4.458 cm . The return tests show ed that the highest ±1SEEaccuracy of the m ultiple regression equation:y=83.959+3.589 x6+2.573 x2, w ere 30%;and the highest ±2SEEaccuracy of the m ultiple regression equation: y=72.646+3.316 x6+1.586 x2+1.553 x4+2.211 x3, w ere 92% . Conclusion There is significant linear correlation betw een 7 selected lines and the stature in this study, and the plural linear regression equation established could be applied for estim ating the stature of Southw est H an m ales.