DNA extraction and quantification from human saliva deposited on fruits with human bite

摘要

Background: Among important aspects of forensic science there stand recovery,preservation and analysis of stains originated by body fluid. DNA Isolated from evidencestains help to exclude an innocent suspect or to identify a perpetrator upon PCR-based typing.This study reports extraction and quantification of DNA from human saliva deposited onfruits. The research work was conducted at Department of Forensic Sciences, University ofHealth Sciences, Lahore and WTO laboratory of University of Veterinary and AnimalSciences, Lahore.Methodology: DNA from saliva deposited on bitten fruits. DNA from 55 samples wereextracted by Chelax method, Quantifiler? DNA Quantification Kit was used forquantification of the extracted samples and amplification of DNA was done in 7500 Real-Time PCR systems (Applied Biosystems, Foster City, CA). Total 55 samples includingcontrols (positive and negative controls) were collected from bitten fruits by sterile swabs.Results: All sample swabs with human saliva showed result for quantification. Overall goodyield of DNA quantification obtained from all fruits and no sample showed internalinhibition. No sample showed non informative or incomplete quantification which occurs dueto LCN (Low copy number) or lesser quantity of DNA extracted from saliva swab.Conclusion: This study has provided with optimized protocol to isolate DNA from salivafound in very minute quantity on organic surfaces like fruits. Adaptation of this method canplay a vital role in establishing new trends in human forensics practiced in Pakistan.Moreover, for future work in human forensics, this study can provide important practicalbasis.