DNA extraction from decomposed tissue by double-digest and magnetic beads methods / 法医学杂志

OBJECTIVE@#To study the effect of the double-digest and magnetic beads method for DNA extraction from 3 types of decomposed tissues.@*METHODS@#DNA of cartilages, nails and joint capsule in 91 highly decomposed corpses which had not been extracted by common magnetic beads method, were prepared with the double-digest and magnetic beads methods, and quantified with Quantifiler kit, followed by amplification with Sinofiler kit or Minifiler kit.@*RESULTS@#DNA concentration extracted from the 91 highly decomposed cartilages, nails and joint capsule samples was 0-0.225 ng/microL. Sixty-two samples whose DNA concentration were more than 0.020 ng/microL had obtained 9 or more STR loci successfully. The detection rate was 68.13%.@*CONCLUSION@#The successful rate of STR genotyping for the 3 types of decomposed tissues can be significantly improved by the double-digest and magnetic beads methods.

Application of a new magnetic beads made in China in DNA extraction of forensic biological samples with automation workstation / 中国法医学杂志

Objective To study the application of a new magnetic beads made in China in DNA extraction of forensic biological samples with automation workstation.Methods DNA was extracted from common forensic biological samples by QIAGEN Bio-Robert Universal System and a new magnetic beads made in China,and then typed with Identifiler system in ABI3130XL Genetic Analyzer.210 of these samples were also quantitated by ABI7500 Real Time System.Results Total of 9100 genomic DNA was extracted from various forensic biological samples by the new magnetic beads made in China and automation workstation methods,and most of them were successfully typed for STR analysis.In these biological samples,oral swabs and muscles were of the highest Success rate of STR typing(100%),and the lowest was touched cell samples (50.0%).Conclusion The new magnetic beads made in China with automation workstation methods can be applied to DNA extraction of most forensic biological samples.

DNA typing of minimal oral epithelial cell samples / 法医学杂志

OBJECTIVE@#To seek simple and cost-effective extraction technique to improve multiplex STR amplification from minimal oral epithelial cell samples.@*METHODS@#One hundred DNA samples of oral epithelial cells extracted by mini system Chelex-100 method were quantitated by ABI 7500 Real Time System and were then typed with Identifiler system in ABI 3130 Genetic Analyzer.@*RESULTS@#The DNA contents of different categories of samples were as followings: suck pipes (0.72-116.78 ng), cup edges (2.15-142.5 ng), mouths of drink bottle (1-34.65 ng), chopsticks (3.35-26.6 ng), fruit cores (0.294-21.4 ng), and poultry bones (0.88-5.88 ng). The mean successful typing rate for gender and more than 9 STR loci was about 59.38%. Except the addition or no addition of proteinase K to the samples, all other factors-C users' variation, sample extraction methods, and qualities and properties of the samples had considerable effects on the contents of extracted DNA.@*CONCLUSION@#Successful STR typing can be achieved in about 60% minimal oral epithelial cell DNA samples extracted by mini Chelex system.

Genetic studies of 15 STR loci in Guangxi Miao population / 法医学杂志

OBJECTIVE@#The study was carried out to investigate genetic polymorphism of 15 STR loci in Guangxi Miao population. METHORDS: DNA samples from southern China 274 Miao unrelated individuals were screened by using AmpFlSTR Identifiler PCR Amplification Kit and 3100 Genetic Analyzer.@*RESULTS@#These 15 loci meet the Hardy-Weinberg expectations. The matching probability of the 15 STR loci was 5.04 x 10(-17), and combined paternity of exclution was 0.9999993 in Guangxi Miao population.@*CONCLUSION@#Our results showed Identifiler PCR Amplification systems of 15 STR loci were useful enough to forensic case work in Guangxi Miao population.

Genetic polymorphic studies on 15 loci of 3 populations in Guangxi province / 中国法医学杂志

Objective To study the genetic polymorphism of 15 STR loci of 3 populations in Guangxi province. Methords DNA samples of unrelated individuals from 314 Gelao population,332 Mulao population,238 Yao population were analyzed using AmpFlSTR IdentifilerTM PCR Amplification Kit and 3100 Genetic Analyzer. Results The matching probability of the 15 STR loci was 1.839 ?10-16 ~ 5.073 ? 10 -17 and combined paternity of exclusion was 0.9999983 ~ 0.9999991 in the 3 populations. Conclusion The results showed that the 15 STR loci in Identifiler?PCR Amplification systems were useful for forensic case works in Gelao population, Mulao population and Yao population .

Real time PCR quantificational study of DNA extracted by Chelex-100 method / 中国法医学杂志

Objective To study the relation between the quantity of DNA extracted by Chelex-100 method and multiplex STRs analysis.Methods DNA extracted from a variety of common forensic casework specimens were quantified by using Real-time PCR,and then amplified with AmpFLSTR IdentifilerTM PCR Amplification kit.ResultsAccording to the results of quantification,the quantities of DNA extracted from 113 samples by Chelex-100 method were adjusted to 0.5~3ng for establishing 8?l amplification system,and in this condition,most of 113 forensic casework specimens could be successfully genotyped.Conclusion When the quantity of DNA extracted by Chelex-100 method ranged from 0.5ng to 3ng,most results of multiplex STRs analysis were satisfying.Moreover,the amplification effect of 1?l DNA template was better than 3?l DNA template when the concentrations of extracted DNA were more than 0.5ng/?l.