The aim of this study was to evaluate the forensic protocol recently developed by Qiagen for the
QIAsymphony automated DNA extraction platform. Samples containing low amounts of DNA were
specifically considered, since they represent the majority of samples processed in our laboratory. The
analysis of simulated blood and saliva traces showed that the highest DNA yields were obtained with the
maximal elution volume available for the forensic protocol, that is 200 ml. Resulting DNA extracts were
too diluted for successful DNA profiling and required a concentration. This additional step is time
consuming and potentially increases inversion and contamination risks. The 200 ml DNA extracts were
concentrated to 25 ml, and the DNA recovery estimated with real-time PCR as well as with the
percentage of SGM Plus alleles detected. Results using our manual protocol, based on the QIAamp DNA
mini kit, and the automated protocol were comparable. Further tests will be conducted to determine
more precisely DNA recovery, contamination risk and PCR inhibitors removal, once a definitive
procedure, allowing the concentration of DNA extracts from low yield samples, will be available for the
QIAsymphony.