Preventing DNA Contamination in Forensic Laboratories: An Illustrated Review of Best Practices

Abstract

Forensic DNA analysis has become a cornerstone of modern criminal investigations, offering unparalleled capabilities in linking suspects to crime scenes, exonerating the innocent, and solving cold cases. However, the reliability of DNA evidence is intrinsically linked to the integrity of the sample throughout the forensic process. Contamination, whether from cross-sample transfer, environmental sources, or human error, poses a significant risk to the accuracy of forensic results, potentially leading to wrongful convictions or the acquittal of guilty individuals. The advent of advanced techniques such as Low-Copy Number (LCN) and Touch DNA analysis has further amplified these risks, as the increased sensitivity of these methods makes them particularly vulnerable to contamination and secondary DNA transfer.

This review comprehensively examines the best practices for preventing DNA contamination in forensic laboratories, with a focus on the unique challenges posed by LCN DNA analysis. Key areas covered include laboratory design and layout, the proper use of personal protective equipment (PPE), meticulous sample handling protocols, and rigorous environmental monitoring. The importance of stringent quality control measures, continuous training, and strict adherence to Standard Operating Procedures (sops) is emphasized to ensure that these practices are consistently implemented. Additionally, the review highlights the role of illustrated summaries, such as flowcharts and mind maps, as effective tools for education, and training, helping to reinforce these best practices.

By adopting these comprehensive strategies, forensic laboratories can significantly reduce the risk of DNA contamination, thereby upholding the credibility of forensic DNA analysis. This, in turn, strengthens the integrity of the criminal justice system, ensuring that DNA evidence continues to serve as a reliable and powerful tool in the pursuit of justice.