000 02824nam a2200241 4500
001 390997
090 _a390997
100 _a20120601d2009 y0pory50 ba
101 _aeng
200 _aDouble strand break repair of highly damaged DNA
_bRecurso eletrónico
_efinal report
_fJack Ballantyne
210 _a[Orlando, FL]
_ced. do a.
_d2009, 2011
215 _a1 CD-ROM
_d12 cm
300 _aResearch report submitted to the Department of Justice, National Institute of Justice - Award Number: 2006-DN-BX-K005. Ficheiro de 933 KB em formato PDF (98 p.). Disponível também em: https://www.ncjrs.gov/pdffiles1/nij/grants/236690.pdf. Acedido a 01 de junho de 2012.
330 _aDNA extracted from biological stains is often intractable to analysis. This may be due to a number of factors including a low copy number of starting molecules, the presence of soluble inhibitors or damaged DNA templates. Remedies may be available to the forensic scientist to deal with LCN templates and soluble inhibitors but none presently exist for damaged DNA. Previous work in this laboratory has shown that double strand and single strand breaks are significant contributors to the non-typeability of damaged DNA templates extracted from forensic-type stains (i.e. dried biological stains exposed to a myriad of environmental insults). This proposal sought to repair double strand breaks, restoring sufficient genomic integrity to permit DNA typing, using single nucleotide polymorphism loci (SNPs) as a model system. Three methods were developed and tested. The first is a simple gap filling prior to strand denaturation during the DNA amplification process. The second requires the addition of in vitro synthesized repair substrates that are complementary to the sequences flanking a SNP on both DNA strands, providing a matrix for repair polymerization and facilitating the recovery of amplifiable fragments. The third method involved the biochemical reconstitution of the non-homologous end joining (NHEJ) pathway, one of the principal cellular recombinational DNA repair pathways. While the substrate mediated gap repair system demonstrated some evidence of in vitro repair using artificial genomic templates, all attempts at repair of genomic DNA using any of the repair methods failed. We believe that the sequence complexity of genomic DNA provides an insurmountable computational barrier to reconstituting two contiguous fragments of DNA back to its native state, a requirement for the successful repair of double strand breaks.
606 _aPRESERVAÇÃO DA PROVA
_9302776
606 _aADN
_9243660
606 _aANÁLISE DE VESTÍGIOS
_9320649
606 _aBIOLOGIA FORENSE
_91092
700 _aBALLANTYNE
_bJack
_9145740
955 _xOferta