Dna in Forensic Science

By: J.J. Yong

Since the introduction of DNA testing as evidence in 1990, criminal justice system has been improved but mistakes and human errors have downplayed the effectiveness of the technology.

This DNA forensic has undeniably helped in solving tough cases and yet, public awareness of the information is only surface touching depth.

Forensic identification tests can link the DNA segments to each individuals existing.

Examples of DNA uses in the field include identification of potential suspects whose DNA maybe match leftovers at crime scenes, establishment of paternity and family relationships of victims whom could not be recognized based on their outlooks and matching organ donors with recipients in transplant programs.

The selected interesting cases of DNA forensic identification involve the DNA Shoah Project, identification of the 911 and South East Asia 2004 Tsunami victims and others.

There have been two main types of forensic DNA testing. They are often called; RFLP and PCR based testing, although these terms are not very descriptive.

Generally, RFLP testing requires larger amounts of DNA and the DNA must be under graded. Crime-scene evidence that is old or that is present in small amounts is often unsuitable for RFLP testing.

Warm moist conditions may accelerate DNA degradation rendering it unsuitable for RFLP in a relatively short period of time.
PCR-based testing often requires less DNA than RFLP testing and the DNA may be partially degraded, more so than is the case with RFLP. However, PCR still has sample size and degradation limitations that sometimes may be under-appreciated.

PCR-based tests are also extremely sensitive to contaminating DNA at the crime scene and within the test laboratory.

During PCR, contaminants may be amplified up to a billion times their original concentration. Contamination can influence PCR results, particularly in the absence of proper handling techniques and proper controls for contamination.

PCR is less direct and somewhat more prone to error than RFLP. However, PCR has tended to replace RFLP in forensic testing primarily because PCR based tests are faster and more sensitive.

Science cannot yet provide conclusive results on genetics and behavior. Discovering more about ourselves to the basic components can reveal much more about us.

Blood group, originality, race, allergies, genetic dominance and other elements just showed that we are fascinating creatures to exist on earth.

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