The integrity and assay performance of tissue mitochondrial DNA is considerably affected by choice of isolation method

The integrity of mitochondrial DNA (mtDNA) isolated from solid tissues is critical for analyses such as long-range PCR, but is typically assessed under conditions that fail to provide information on the individual mtDNA strands. Using denaturing gel electrophoresis, we show that commonly-used isolation procedures generate mtDNA containing several single-strand breaks per strand. Through systematic comparison of DNA isolation methods, we identify a procedure yielding the highest integrity of mtDNA that we demonstrate displays improved performance in downstream assays. Our results highlight the importance of isolation method choice, and serve as a resource to researchers requiring high-quality mtDNA from solid tissues.

Automated summary

This study demonstrates that commonly-used isolation procedures for mitochondrial DNA (mtDNA) result in mtDNA with single-strand breaks. By comparing different DNA isolation methods, a procedure is identified that yields the highest integrity of mtDNA and shows improved performance in downstream assays. These findings emphasize the importance of choosing the right isolation method for obtaining high-quality mtDNA from solid tissues.