DOI: https://doi.org/10.55373/mjchem.v25i3.400

Keywords: Fabrics; DNA; tap water; lake water; river water; sea water

Abstract

Biological fluid especially human blood is a type of evidence that plays a major role in criminal investigations. However, there are challenges in performing blood DNA analysis due to environmental factors and criminal acts that affect DNA stability. This usually happens when dead bodies of victims are subjected to water or land burial. Samples found in such crime scenes often lack sufficient evidence due to DNA degradation or contamination. The aim of this research is to study the persistence of DNA extracted from different types of bloodstained fabric samples immersed in different types of water. Ten types of fabrics used for this study were satin, chiffon, linen, polyester, cotton, crepe, argenti, valentro, lycra and georgette. The four water samples were from a lake, a river, the sea, and tap water. The extraction of DNA from bloodstained fabric samples were conducted using NEXPreo Blood DNA Mini Kit. The concentration of extracted DNA were analysed with Eppendorf BioPhotometer Plus. Fabrics immersed in tap water had the highest DNA concentration retention followed by lake water, river water and sea water. Among the ten types of fabrics, synthetic fabrics have better retention of DNA concentrations compared to natural fabrics. The concentrations of DNA from all type of fabrics drastically decreased to almost half of the DNA concentration within 24 hours of immersion for all types of water. This study also showed that underwater DNA loss and DNA degradation was very high within the first 48 hours compared to 72 hours reported in previous studies. Future studies are recommended to reduce the time of immersed fabrics collection to hourly instead of daily so that it could provide more valuable information for crime investigations.