Qualitative and Quantitative Analysis of DNA from Human Saliva Respectively through Quantitative Polymerase Chain Reaction and UV-Visible Spectrophotometer: A Review

Saliva is significant proof that could be found in the location of the crime. The epithelial cells of saliva are the best source of DNA. Forensic DNA phenotyping is the future of Criminal investigations such as Victim or Suspect identification, Paternal Maternity identification, age determination, species identification, etc. Saliva can be found in different places or objects and under different conditions. Saliva could be found on cigarettes, chewing gum, bite marks, water bottle, etc. The quality and the quantity may be varied from sample to sample found in a different place. Environmental factors can also cause the degradation of a cell of saliva. High temperature, pH, and an enzyme found in the environment could be responsible for the denaturation of DNA in cells. In such cases, DNA quality and quantity can be altered. Salivary DNA could be extracted by the phenol-chloroform method. But advanced techniques like the Chelex-100 resin method are considered the best method to extract salivary DNA, providing better quality and quantity. DNA fragments are used for quantitative analysis of DNA through PCR. Digital PCR consumes less time to analyze DNA and made the procedure easy. UV spectrophotometer is widely used for measuring the quality of DNA from mid the twentieth century. The current review article highlights forensic research to measure DNA quality and quantity samples by qPCR, and UV-Vis Spectrophotometer methods from human saliva for further criminal investigations. This article also contributes knowledge to more effective PCRs used to measure DNA quantity.