Uso dos mini-STR NC01 e NC02 na prática forense: (I) validaçao; (II) análise em DNA degradado; (III) estudo populacional no Rio Grande do Sul

Abstract

I offer this thesis, which is fulfill the purposes of the cooperation agreement between the Programa de Pós-Graduação em Biologia Celular e Molecular, PUCRS and Instituto Geral de Perícias, State Security from Rio Grande do Sul, with the intention to establish a routine for molecular identification of human DNA from degraded to be functional and scientific basis. Even with the advances of commercial amplification kits and equipment for DNA extraction and genotyping, forensic samples remain challenging. With the occurrence of massive disasters or the increase in trace samples that will be part of the CODIS database, it is very important that forensic laboratories have the available markers to amplify fragments of small size and the use of miniSTRs may be an important tool for this purpose. The use of miniSTRs for the identification of degraded DNA samples and obtaining the allele frequency of six miniSTRs took place in samples from the population of Rio Grande do Sul for its use in forensics. The validation study was conducted as directed by the Scientific Working Group on DNA Analysis Methods (SWGDAM). The validation is to examine the robustness of miniPlex NC01 and NC02 in forensic cases. This study evaluated factors that potentially affect the results of genotyping obtained by amplification of STRs. The study of forensic samples of degraded DNA was performed with 22 samples of human remains (21 teeth and one bone). Due to the difficult amplification of such samples in forensic laboratories often is necessary to use the technique of sequencing of the mtDNA that is time consuming, costly and only indicates the maternal bond. Thus, the use of miniSTRs NC01 and NC02 in challenging samples proved to be a useful tool in generating human identification profile in all samples. The use of miniSTRs NC01 and NC02, in conjunction with other commercial kits with markers of small size will be of great assistance to the Forensic Scientists. With the study population as possible is the immediate use of these markers for forensic and criminal cases in the identification of family linkages, increasing the odds obtained by the statistical calculations.