Short Tandem Repeat (STR) DNA Analysis for Using Coffee Cups As Forensic Medicine Evidence

Introduction Forensic science has continually evolved, with innovations in DNA analysis techniques playing a pivotal role in improving the accuracy and reliability of criminal investigations. Short tandem repeats (STRs) have been a game-changer in forensic science, offering unique genetic markers to pinpoint individual identities. This study explores the application of STR DNA analysis to an unconventional source: coffee cups. Materials and methods In a study involving 16 unrelated, healthy individuals aged 26 to 32, DNA was investigated from coffee cups and mouth cavities, comparing the results to a previous coffee cup DNA study. Buccal swabs provided reference samples, air-dried for 10 minutes, and stored at 20°C. DNA quantification revealed a significant decrease in coffee cup samples (0.015 to 0.049 ng/μL) compared to the reference, with no DNA in negative controls. Some STR loci displayed inhibition and lower heterozygosity in the research samples. Ethical approval (REC 53-592) and adherence to the Declaration of Helsinki ensured ethical standards. This research highlights potential challenges in obtaining efficient DNA profiles from various sources. Results There was a significant variation in DNA concentrations among the different cup types, with ceramic cups yielding the highest concentrations. Moreover, the DNA profiling outcomes ranged from full profiles, which allow for precise individual identification, to partial profiles, which pose challenges for conclusive matches. These findings have profound implications for forensic science. The study demonstrates the potential of coffee cups as sources of DNA evidence in criminal investigations, even if partial profiles are obtained. Such evidence can assist in suspect identification, victim profiling, and corroborating witness statements. Conclusion This study highlights the application of STR DNA analysis for coffee cups, opening new avenues for forensic investigations and highlighting the need for continued research and development in this exciting field. This observation aligns with existing research on DNA recovery from various surfaces, and further research is warranted to refine the methodology, consider usage patterns, and address ethical and legal concerns regarding the collection and use of DNA evidence from common objects.