Journal de recherche médico-légale

Generating Human DNA Profile(s) from Cell Phones for Forensic Investigation

Abstract

Khalid Mahmud Lodhi, Robert Grier IV, Sabrina Davis, Stefanie Phillips and Mohammad Atif Lodhi

The goals of this study were to investigate whether sufficient amount of human DNA can be recovered from a cell phone and if the identity of the single and/or multiple user(s) can be established by generating genetic profile(s). Cell phones were used to collect human DNA. Two Buccal swabs were used to collect Buccal cells as a DNA reference samples. Four soaked sterile cotton swabs were used to collect biological materials from each user’s cell phone. Sufficient quantity and quality of human genomic DNA was obtained from the cell phones using Quantifiler® Human DNA Quantitation Kit. More human DNA was collected from volunteers’ Buccal swabs (=74.56 ng) than from the surface of their cell phones (=0.23 ng). One nanogram (1 ng) of template DNA was used for buccal swabs and cell phones swabs, if available. However, when the DNA recovered from cell phone swabs was 0.00 to 500 pg, 10 μL of template DNA was used. In addition, the number of PCR cycles was increased from 28 to 32 in anticipation of Low Copy Number DNA. Genetic profiles were developed from the DNA on the cell phones and were compared with the reference DNA profiles from the buccal cells of the cell phone owners. Full Short Tandem Repeats (STR) DNA profiles for all 15 STR loci plus Amelogenin locus were typed for 36 Buccal swabs, reference DNA of cell phone owners. Complete STR profiles were generated from 33% (N=36) cell phones and were matched participants’. In addition, 28% of cell phones had partial DNA profiles matched with the cell phone owners. While, 33% of the cell phones had unknown partial or complete profiles. Four of the unknown partial profiles had more than two alleles at
the STR loci indicating multiple unknown cell phone users. The Y chromosome was detected at the Amelogenin locus from the DNA profiles generated from two females’ cell phones identifying unknown male contributor(s). Our study demonstrates that DNA collected from the cell phones can be used as reliable physical evidence in forensic investigations.