Authors
Sweety Santra, Arun Kumar K
Abstract
It’s a common practice for perpetrators, washing blood stains with different types of water and detergents, to remove blood evidence and traces at the scene of the crime. Multiple studies carried out around the world have shown that DNA is present in washed blood stains, which show that protective blood cell structures are often able to shield them from degradation of DNA. In this study, we used pig skin, smudged with mice blood, and were kept in four different containers labelled as fresh water, salt water, fresh water with detergent and salt water with detergent with variable pH condition for 6 hours, 12 hours and 18 hours to check the persistence of DNA. A total number of 12 samples were used. All in all, the results demonstrate that specifically those samples which was immersed in fresh water, was possible for extraction of DNA. The samples which were immersed in other aquatic conditions was not viable for extraction of DNA. As detergents contain enzymes that are designed to break down biological molecules including DNA and increased pH in these systems enables DNA to get denatured faster compared to salt water and fresh water system. Keywords: DNA, Persistence, Aquatic condition, Immersed sample, Forensic, Detection
Introduction
Identifying and determining the origin of blood stains in various crimes forms important physical evidence. Forensic scientists must examine every type of material recovered under many different conditions for the purpose of determining whether blood is present (Jain and Singh, 1984). Water is an important factor affecting DNA integrity (Frippiat et al., 2017). Forensic evidence from blood is highly valuable and has been a determining factor for solving many criminal cases (Wickenheiser, 2002).
The presence of a bloodstain is primarily observed as biological evidence at the crime scene, particularly in violent crimes (Sapan et al., 2021). Touch DNA and Trace DNA is the type of DNA commonly found in the crime scenes and the most missed evidence. The amount of DNA transferred is affected by numerous factors, some of which may be intrinsic to the individual, such as shedder status (Lowe et al., 2002). Temperature extremes affect the degradation profile of bloodstains (Cossette et al., 2021). The cleaning agents lead to the degradation of DNA and also cause changes in DNA structure. The DNA double strand will also get affected by the influence of detergent (Judah et al., 2023).
Examining bloodstains is of immense value in reconstructing a crime scene and linking the perpetrator or victim to the crime scene. criminals today often try to clean up the crime scene, and it is not known under what conditions the bloodstain passed before the analysis. The detection of bloodstains can be done with the help of luminol as it does not have any destructive effect on the extraction of DNA as well on the blood test (Passi et al., 2012).
The aim of the study was to extract the DNA from the pig skin after been kept in a particular aquatic sample (i.e. fresh water, Salt water, fresh water with detergent & Salt water with detergent) for 6, 12 & 18 hours.
References
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How to cite this article?
| APA Style | Santra, S., & Kumar K, A. (2024). Study on Persistence and Detection of Blood Stain DNA on Pig Skin Exposed to Different Aquatic Conditions. Academic Journal of Forensic Sciences, 07(01), 10–13. |
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