Using The Oxford Nanopore MinION MK1B sequencer to identify human and animal DNA

Abstract

Animal DNA is valuable to forensic science research and development because it lends strong evidence that can be used to potentially include or exclude a person from involvement in a crime. Oxford Nanopore sequencing is considered a highly innovative tool used for forensic applications, but present-day knowledge and documentation of animal sequencing using this device is limited. Examples of previous studies where animal species were positively identified exist; however, due to limitations of current technology and research, it has not always been accurate. This research investigates if the Oxford Nanopore MinION MK1B sequencer can correctly identify human versus animal DNA from a mixture. Using the innovative Oxford Nanopore Technology, four samples were analyzed using human DNA (NA12878) and dog DNA (GDM-150). One sample was 100% human DNA, one sample was 100% dog DNA, one was a 75% dog 25% human DNA mixture, and one was a 75% human 25% dog DNA mixture. Mixtures are evidence samples containing DNA from more than one individual. The procedure included DNA library preparation, DNA quantification, sequencing in MinKNOW, flow cell wash, and data analysis in EPI2ME software. FASTQ files from sequencing were converted to BAM files using the EPI2ME workflow wf-alignment. The BAM files were then uploaded to IGV for analysis against a reference genome of human and dog DNA. Based on analysis in IGV and the wf-metagenomics workflow, the dog DNA was the major contributor in the samples that were predominately dog, and the human DNA was the major contributor for the samples that were predominately human. This study demonstrates that ONT can be used to identify different species successfully.