Comparing Two Automated Methods of DNA Extraction from Degraded Skeletal Remains

DNA extraction from degraded skeletal samples is often particularly challenging. The difficulty derives from the fact that variable environment has a significant effect on DNA preservation. During the years 2002-2015 unidentified degraded skeletal remains were accumulated at our institute, National Institute of Forensic Medicine (NIFM), most of them with none or partial DNA profile. As new methods rapidly emerge, we revisited these samples with partial DNA profiles in the hope to add additional alleles and eventually be able to identify these previously unidentifiable samples. We have chosen to use these samples to compare two automated methods: Prepfiler Express BTA (Applied Biosystems) and QIAcube (Quiagen), in hope of acquiring a more complete DNA profile and eventually make new identifications possibly comparing these profiles with missing person database. In both methods, a preparation step is required, after which the samples undergo automatic DNA extraction. The two protocols are based on different extraction methods. Fresh or non-problematic bone samples as the positive control gave the same results in both methods. In the degraded skeletal samples, the results were significantly better using the QIAcube method in our hands, but since degraded samples are highly variable the combination of both methods could be useful to receive better and more reliable profiles.