Forensic DNA technology: A powerful tool for judicial reform

Written by Ma. Corazon A. de Ungria, PhD
25 January 2013

Photo credits: Philippine Genome Center
DNA testing is the most powerful tool for human identification. Since its discovery in the mid-1980s, DNA profiling had caused a paradigm shift in the identification of victims, perpetrators and witnesses in numerous cases. The identification of genetic markers that are highly variable in human populations is a major step toward the establishment of reference as well as criminal databases needed for statistical evaluation of matching DNA evidence, or identification of repeat offenders, respectively. In addition, the chemical stability of a DNA molecule against harsh environmental challenges such as extreme temperatures and high humidity makes it more suitable for criminal investigations which lasts for months, even years in the Philippines. Moreover, the fact that a person inherits one’s DNA from one’s parents, provides an investigator with alternative reference samples, when an individual’s own reference biological sample is unavailable.

Recent advances in forensic DNA testing are now paving the way for reforming the manner by which cases are resolved in courts of law through the way suspected offenders are apprehended during a criminal investigation. Firstly, the availability of new markers which are more variable across different populations, adds to the increased power of discrimination once more genetic markers are used. From the time when DNA testing only involved seven to nine genetic markers to evaluate if crime scene evidence matches a suspect’s profile, as well as to determine relationships, to the current battery of 21 autosomal markers and 23 male-specific markers, the capacity of DNA profiling to differentiate individuals has increased significantly. The use of automated and expert systems for large-scale analysis has also been found to reduce manual errors and to increase output per unit time. The use of several dyes in a single multiplex system provides more information from the same amount of genetic material compared to reactions targeting only one genetic marker but requiring the same amount of DNA that was common in the early 1990s.

Read Full Article

About the Author
The author received the NAST Outstanding Young Scientist Award in 2003 for Molecular Biology. She is the current head of the DNA Analysis Laboratory, Natural Sciences Research Institute of UP Diliman and the director of the Program on Forensic and Ethnicity of the Philippine Genome Center. She Ungria has appeared as expert witness in cases involving disputed parentage issues and in relation to criminal cases. She provided her technical assistance during the formulation of the Rule on DNA Evidence and her opinion on different bills regarding forensic DNA technology. The UP-NSRI DNA Laboratory continues to offer its parentage testing and DNA profiling expertise as part of its commitment to serve the community.