Fast mitochondrial DNA isolation from mammalian cells for next-generation sequencing

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Standard mitochondrial DNA (mtDNA) extraction methods lack sufficient enrichment for direct sequencing.
• Conventional protocols often require long-range PCR amplification, which can introduce bias into sequencing results.

Purpose of the Study:

• To develop a fast, cost-effective, and reliable method for preparing enriched mtDNA samples from eukaryotic cells.
• To enable direct sequencing of mtDNA without significant PCR-induced bias.

Main Methods:

• Utilized a conventional miniprep kit combined with paramagnetic bead-based purification.
• Incorporated an optional, limited PCR amplification step for mtDNA.
• Quantified enrichment using real-time PCR and assessed sequencing reads alignment.

Main Results:

• Achieved over 2000-fold enrichment of mtDNA compared to total cellular DNA with the first two steps alone.
• Demonstrated ~200-fold greater enrichment compared to current commercial kits.
• Obtained >99% of sequencing reads aligned to mtDNA after 10 cycles of PCR, compared to 22% for non-amplified samples.

Conclusions:

• The described protocol offers a significant improvement in mtDNA enrichment efficiency.
• This method provides a reliable and less biased approach for preparing samples for direct mtDNA sequencing.
• The protocol is suitable for applications requiring high-purity mtDNA for sequencing.