The developments in generation of DNA profiles - Assignment Example

The changes occurring in the modern world make use of weapons of mass destruction exemplified by nuclear, chemical and biological weapons. The advanced weaponry is likely to result into disasters of great magnitudes as typified in armed conflicts and acts of terrorism (Zietkiewicz, Witt, Daca, Zebracka-Gala, Goniewicz, Jarzab & Witt, p41, 2012). A critical issue during disaster response involving a multitude of individuals is the need to identify victims. Various catastrophic events including the World Trade Center (WTC) disaster, Asian Tsunami and the Hurricane Katrina have offered immense knowledge regarding the effectiveness of the STR and mitochondrial DNA sequence analysis on highly compromised samples (Eisenberg & Planz, p12, 2007).

Human identification has made tremendous strides over the past two decades. Since the inception of forensic DNA analysis, there have been two main objectives. These are the identification of those who could be the source of biological evidence and to exclude individuals wrongly associated with evidence. The generation of reliable genetic profiles from unknown and reference samples, systematic and objective interpretation practices as well as providing statistical assessment of the outcomes is critical to a robust DNA profiling program (Alvarez-Cubero, Saiz, Martinez-Gonzalez, Alvarez, Eisenberg, Budowle & Lorente, p229, 2012).

The early evolution of forensic genetics has driven the analysis of human genetic variation, beginning more than a century ago. Specifically, with Karl Landsteiner’s discovery of the human ABO blood group polymorphism and his early realization that this variation could be applied in solving crimes (Jobling & Gill, p740, 2004). DNA fingerprinting using the hyper variable loci known as mini-satellites discovered in 1984 by Alec Jeffery was another classical human identification technique. The mini-satellites were detected by hybridization of probes to Southern blots of restriction enzyme digested genomic DNA.

Although the application of DNA fingerprinting lasted for some time in paternity testing, criminal casework soon concentrated on the use of specific cloned mini-satellites called single locus probes (SLPs). These revealed only a single, highly polymorphic restriction fragment length polymorphism, hence simplifying interpretation. The amplification of DNA by polymerase chain reaction (PCR), offered an enormous increase in sensitivity. These molecular based approaches allowed small amounts of degraded DNA to be analyzed at a rapid rate (Jobling & Gill, p740, 2004).

PCR-based techniques allowed the targeting of numerous genetic markers from single-nucleotide polymorphisms (SNPs) to variable number of tandem repeats (VNTRs). The testing of human identity may be considered in a variety of contexts namely analysis of relationship, forensic casework, missing person investigation and mass casualty incident (MCI) victim identification (Zietkiewicz, Witt, Daca, Zebracka-Gala, Goniewicz, Jarzab & Witt, p42, 2012). Environmental conditions of mass casualty identification usually lead to severe fragmentation, degradation and intermixing of the remains of victims.

Under such conditions, conventional methods of identification that depend on physical and anthropological characteristics of the victims fail. Consequently, DNA profiling has become a gold standard for the identification of victims in mass casualties or forensic related cases.