Touch DNA vs. Biological Fluids: Sensitivity, Reliability, and Forensic Implications

DOI

10.2991/978-94-6239-610-4_49How to use a DOI?

Keywords

Touch DNA; Biological fluids; visible biological evidence; DNA profiles

Abstract

Touch DNA has become an important part of forensic investigations because it can reveal genetic material from objects someone has simply handled. At the same time, it’s not easy to work with. The amount of DNA left behind can be very small and unpredictable, which makes collection and interpretation tricky. This review looks at thirty studies that explored how touch DNA is deposited, how it can move between surfaces, and the ways forensic examiners recover and interpret it in real cases. Many factors influence how much touch DNA ends up on an object. Some people shed more skin cells naturally, while others leave very little. The type of surface matters too—rough or porous surfaces usually retain more DNA than smooth ones. How long a person touches something, how firmly they press, and even environmental conditions like heat and humidity all play a role. Because of this, touch DNA is especially useful in cases where there’s no visible biological evidence, like blood or saliva. Biological fluids, on the other hand, usually produce stronger, more complete DNA profiles, which makes them more reliable for connecting suspects, victims, and crime scenes. Even so, touch DNA fills an important gap when only small or trace amounts of material are available. Using both together helps investigators reconstruct events more clearly, check witness statements, and confirm physical contact. In this way, touch DNA and fluids complement each other, giving a better overall picture of what happened at a scene.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - K. Gopika
AU  - C. S. Anantha Lakshmi
AU  - P. N. Varshini
AU  - M. Synthia
PY  - 2026
DA  - 2026/05/05
TI  - Touch DNA vs. Biological Fluids: Sensitivity, Reliability, and Forensic Implications
BT  - Proceedings of the First International Conference on Advances in Forensics and Cyber Technologies (ICFACT 2025)
PB  - Atlantis Press
SP  - 586
EP  - 615
SN  - 2352-538X
UR  - https://doi.org/10.2991/978-94-6239-610-4_49
DO  - 10.2991/978-94-6239-610-4_49
ID  - Gopika2026
ER  -