Entomological Specimens Obtained from Human Remains offer a Faster Option for DNA Identification

Abstract

Genetic identification of human remains in advanced stages of decomposition traditionally involves the extraction of DNA from a toenail, bone, or tooth.  This extraction protocol typically relies on an overnight incubation and may yield a degraded, unusable DNA profile.    Insect life on the remains may provide an equally viable, yet often overlooked means to obtain a DNA profile in a shorter amount of time.  This study conducted at the Arkansas State Crime Laboratory (ASCL) examines the possibility of obtaining human DNA from the entomological specimens that accompanied the remains.  It also examines the incubation time of the specimens and the class of insects from which a profile could be obtained.  Fly and beetle larvae were initially frozen before extraction using the following instruments:  Qiagen DNA Investigator Kit in conjunction with the Qiagen EZ1 robotic workstation, Qiagen Quantiplex Pro in conjunction with the Applied Biosystems 7500 Real-Time PCR Instrument, Promega PowerPlex Fusion 6C kit with an Applied Biosystems Veriti Thermal Cycler, and finally an Applied Biosystems 3500xL Genetic Analyzer.  Of the fifteen samples of insect life collected, fly larva (Diptera) yielded four usable profiles.  The beetle larva (Coleoptera) specimens yielded no usable profiles.  Using insect-harvested DNA to identify human remains, in some cases, allows for a faster turnaround time so that remains can be released for mortuary care as quickly as possible.