Fighting passport fraudulence using DNA analyses

Passports are the number one form of individual identification when crossing borders resulting in counterfeit or modified passports being used to allow illegal travel. Here we report on the use of Diamond Dye to detect cells deposited by touch onto parts of the photograph page of a passport. The passport page was divided into a grid of 11 rectangles of approximately equal dimensions. Thumbprints were deposited at 10 of the 11 squares, with the 11th left blank as a negative control. The location and number of deposited cells were determined and recorded. Cellular material was removed from each square separately, using a moistened swab or a tapelift. Tapelifting was better suited for the substrate resulting in an increase in DNA recovered. The highest total quantity of DNA isolated from the 10 samples post extraction was 0.162 ng. Short tandem repeat data were obtained from all 10 samples using the GlobalFiler^TM PCR Amplification Kit. The DNA profiles were single source or two-person mixtures and the donor was always the major contributor. These data show the potential to visualize cellular material deposited by touch and then generate STR data from an item such as a passport after only brief physical contact.