Forensic Genetics as a Tool for Peace and Justice: An Overview on DNA Quantification
- *Corresponding Author:
- Cláudia Vieira da Silva
Serviço de Genética Forense
Instituto Nacional de Medicina Legal
Delegação do Sul, Lisboa, Portugal
E-mail: [email protected]
Received Date: November 20, 2012; Accepted Date: December 29, 2012; Published Date: December 31, 2012
Citation: da Silva CV, Costa HA, Santos JC, Espinheira RM (2013) Forensic Genetics as a Tool for Peace and Justice: An Overview on DNA Quantification. J Forensic Res S11:008. doi:10.4172/2157-7145.S11-008
Copyright: © 2013 da Silva CV, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In Forensic Genetics, DNA analysis is performed to obtain a Short Tandem Repeat (STR) profile from an evidence sample, which is then compared with the victim and suspect(s) reference sample STR profile, to determine their contribution for that evidence sample. However, forensic biological samples can be present in low quantities, and be exposed to different environmental insults leading to DNA degradation and contamination by inhibitor compounds. Thus, it is desirable for the forensic scientist to have useful information about the forensic sample quantity and quality prior to STR amplification. New methods in Forensic DNA analysis for detecting, preserving and quantifying DNA, as well as its recover from different biological material are continually being developed. Real Time PCR (RT-PCR) assays for DNA quantification, like the recent Quantifiler® Duo DNA quantification kit (Applied Biosystems) proved to be very useful in forensic samples. Since many samples, mainly those resulted from sexual assault cases are often composed by unbalanced male/female DNA mixtures, the knew RT-PCR quantification assay, developed to quantify relative male/ female DNA ratio, contributes not only for total DNA determination, but also to ascertain the presence and quantity of enough male DNA in the sample. These results are important to guide for the optimal STR analysis selection, such as autossomal STR, Y-STR or mini-STR, increasing downstream analysis success rates. In this work we present real forensic caseworks where the DNA amount and quality was important to guide for the selection of the appropriate STR amplification kit in order to increase the success of profiling in the first attempt, reducing the number of samples that need to be reprocessed and thereby decreasing the turn around time in a forensic laboratory.