Human short tandem repeat identification using a nanopore-based DNA sequencer: a pilot study.

Area of Science:

• Genomics
• Forensic Science
• Molecular Biology

Background:

• Short tandem repeats (STRs) are crucial for personal identification in forensics.
• Capillary electrophoresis is standard, but DNA sequencing offers higher resolution for identifying iso-alleles.
• Nanopore sequencing presents a portable alternative for genetic analysis.

Purpose of the Study:

• To evaluate the performance of the portable MinION nanopore sequencer for human STR genotyping.
• To develop a novel scoring scheme to interpret low-quality MinION sequencing data for STR analysis.
• To assess the accuracy of genotyping and iso-allele identification using this portable sequencing method.

Main Methods:

• Human DNA samples were genotyped for 21-45 STR loci using the MinION nanopore sequencer.
• A custom scoring scheme was developed to manage the lower sequence quality from MinION.
• Reads were analyzed to determine STR repeat numbers and identify nucleotide variations.

Main Results:

• An average of 857,000 reads per sample were generated across seven human samples.
• The developed method achieved 75.7% accuracy for STR genotyping.
• Iso-allele identification accuracy reached 82%.

Conclusions:

• Portable nanopore sequencing with a specialized scoring scheme shows promise for human STR genotyping.
• While accuracy is improved over previous nanopore studies, further optimization is needed for routine forensic application.
• This technology could enhance the portability and accessibility of genetic identification tools.