Page 72 - Veritas - 02.03.22

THE SCIENCE OF

TOUCH DNA

Image courtesy- Image by Gerd

Altmann from Pixabay

Ms. Arsha Sahadevan

Deoxyribonucleic acid (DNA) is an organic, self-replicating molecule that

acts as the carrier of genetic material in organisms. It aids the growth,

development, and reproduction of organisms. Besides identical twins, all

individuals possess unique sequences of DNA. The significance of DNA

evidence arises from this individualistic nature. In a forensic setting, the

conventional sources of DNA include blood, semen, saliva, urine, bone,

and hair.

What is the concept of touch DNA?

The concept of “touch DNA” began gaining acceptance in 1997, when Ro-

land A. H. Van Oorschot and Jones discovered that DNA profiles could

be generated from touched surfaces. Touch DNA, also called trace DNA

or contact DNA, is the DNA obtained from shed skin (epidermal) cells

transferred onto a surface during physical contact like touching. The

amount of touch DNA on a surface of contact can vary between a few

nanograms.