Forensic Significance of Saliva: A Comparative Study of Indoor and Outdoor Cases

Saliva is an increasingly valuable form of biological evidence in forensic investigation, offering critical insights through its rich composition of enzymes, epithelial cells, DNA, and biomarkers. This Review Explores the forensic relevance of saliva by comparing its detectability and DNA integrity in indoor versus outdoor crime scenes. Saliva has become a crucial non-invasive biological fluid in forensic science, offering valuable genetic and biochemical information. Its simple collection process, epithelial cells containing DNA, and applicability across various forensic contexts such as identifying suspects, detecting drug use, and analysing health markers make it a versatile tool. Despite these advantages, environmental factors like temperature, humidity, and exposure time significantly influence the stability and integrity of salivary DNA, particularly in outdoor crime scenes. The study employs a Nanodrop spectrophotometer for DNA quantification and evaluates how environmental degradation influences sample viability, and it highlights the biochemical and physiological properties of saliva that enhance its role in forensic science, while discussing challenges associated with sample collection, preservation, and analysis in variable environments. It examines the forensic significance of saliva, focusing on its composition, diagnostic potential, and susceptibility to environmental factors. Emphasis is placed on comparative studies involving indoor and outdoor saliva samples, utilizing DNA extraction and quantification techniques.