DNA profiles from biological trace material contained in underwear and toothbrushes

Abstract

There are special cases where it is extremely difficult to find a close relative for obtaining reference samples, such as in adoption cases or foreigners without relatives in the country. In these cases, it is possible to use personal objects from the missing person. We developed a protocol for obtaining DNA profiles from toothbrushes and underwear and evaluated two DNA extraction methods (Silica and magnetic particles), comparing the DNA quantity and the quality of the obtained profiles. Results showed that for underwear, silica in suspension recovered higher DNA quantity but magnetic particles (PrepFiler®) generated more complete profiles. For toothbrushes PrepFiler® recovered a higher DNA quantity and generated more complete DNA profiles. Statistical analyses showed there were no significant differences between both methods. Higher DNA quantities were recovered from underwear samples, however toothbrushes generated higher quality in DNA profiles, without obtaining mixed profiles, concluding that toothbrushes are a better item than underwear. Considering that silica in suspension method is three-times cheaper than PrepFiler®, we propose it is possible to successfully obtain DNA profiles from personal objects using a low-cost DNA extract method.