DOI: https://doi.org/10.55373/mjchem.v25i3.407

Keywords: Bloodstained fabrics; DNA; clay loam soil; silt loam soil; sandy soil; loamy sand soil

Abstract

Bloodstained clothing provides important evidence in murder crime scenes as the DNA on clothing can aid in identifying both victims and possible suspects. This is because some homicide cases involve the victims being fully or partially buried in their bloodstained clothes or found with their bloody clothes buried nearby. The aim of this research is to study the persistence of DNA extracted from ten types of bloodstained fabric samples previously buried in four types of soil. The ten types of fabrics used for this study were satin, chiffon, linen, polyester, cotton, crepe, argenti, valentro, lycra and georgette. The soil types used in this study were sandy, silt loam, loamy sand and clay loam soil. The DNA extractions from bloodstained fabric samples were made by using NEXPreo Blood DNA Mini Kit. The concentration of DNA from the extracted samples were analysed by using Eppendorf BioPhotometer Plus. The DNA in linen fabric degraded fastest in all four types of soil as it showed no presence of DNA on day 15 whilst cotton has the highest retained DNA concentration in all soil samples. Sandy soil showed the highest DNA concentration retention for all type of fabrics except linen while clay loam soil showed the most rapid DNA concentration degradation for all types of fabrics. Cotton fabric was able to retain the pure DNA up to day 10 while lycra fabric retained pure DNA only up to day 5 in silt loam soil. Both lycra and georgette fabrics managed to preserve the pure DNA until day 5 in sandy soil. In comparison, only georgette fabric retained pure DNA until day 5 in loamy sand soil. Finally, all types of fabrics buried in clay loam soil were not able to even preserve the pure DNA to day 5. This research indicates that it is critical to locate and retrieve any buried blood-based evidence as soon as possible to prevent further evidence loss due to the varying characteristics of the different types of fabrics and soils which could encourage microbial development as well as provide other ways to degrade DNA.