Evolution of Laboratory Techniques in Forensic Biology: From Conventional Methods to Modern Molecular Approaches

Abstract

During a crime scene investigation biological techniques play very important role in forensic investigations by linking biological evidences to crime events. Traditional identification methods such as chemical & immunological tests have been widely used lab. But these techniques often suffer from many limitations such as low specificity, damaging the evidence or some sensitivity. Recent advances in molecular biology have introduced novel approaches such as RNA profiling & DNA methylation method for more accurate identification of collected samples. Here we summarize conventional & modern techniques used in forensic body fluid identification & discuss their applications in forensic investigations by establishing a connection between sample donors & actual criminal acts. Kind & source of bodily fluids discovered at a crime scene can provide crucial information for crime scene reconstruction. Numerous techniques for identifying bodily fluids have been developed for over a century including protein catalytic activity tests, spectroscopic techniques, chemical tests, immunological tests & microscopy. These traditional techniques for identifying samples are primarily reasonable & only apply to a single bodily fluid at a time. So it has recently been suggested that traditional body fluid identification techniques be replaced with a molecular genetics based approach that uses RNA profiling or DNA methylation detection. The specificity & sensitivity of a number of RNA markers & tDMRs (Tissue-specific Differentially Methylated Regions) that are unique to bodily fluids that are relevant to forensics have been determined using a variety of samples. In this review, we give a summary of the state of the art & the latest advancements in forensic body fluid identification & talk about how it might be used in forensic cases.