Related Experiment Video
Updated: Jun 22, 2026
Two-Step Tag-Free Isolation of Mitochondria for Improved Protein Discovery and Quantification
Published on: June 2, 2023
Biochemical isolation of mtDNA nucleoids from animal cells
1Department of Pharmacological Sciences, University at Stony Brook, Stony Brook, NY, USA.
Abstract:
Mitochondrial DNA (mtDNA) in animal cells is organized into clusters of 5-7 genomes referred to as nucleoids. Contrary to the notion that mtDNA is largely free of bound proteins, these structures are nearly as rich in protein as nuclear chromatin. While the purification of intact, membrane-bound mitochondria is an established method, relatively few studies have attempted biochemical purification of mtDNA nucleoids. In this chapter, two alternative methods are presented for the purification of nucleoids. The first method yields the so-called native nucleoids, using conditions designed to preserve non-covalent protein-DNA and protein-protein interactions. The second method uses formaldehyde to crosslink proteins to mtDNA and exposes nucleoids to treatment with harsh detergents and high salt concentrations.
Insights
Mitochondrial DNA (mtDNA) nucleoids, crucial protein-DNA complexes, are purified using two novel biochemical methods. These techniques reveal mtDNA
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Animal cells organize mitochondrial DNA (mtDNA) into nucleoids, structures surprisingly protein-rich, akin to nuclear chromatin.
- Despite established methods for mitochondrial isolation, biochemical purification of mtDNA nucleoids remains underexplored.
Purpose of the Study:
- To present two distinct biochemical methods for purifying mtDNA nucleoids.
- To facilitate further research into the protein composition and function of mtDNA nucleoids.
Main Methods:
- Purification of native nucleoids preserving non-covalent interactions.
- Crosslinking of proteins to mtDNA using formaldehyde followed by harsh detergent and high salt treatment.
Main Results:
- Successful isolation of mtDNA nucleoids via two alternative biochemical protocols.
- Demonstration of the protein richness of mtDNA nucleoids.
Conclusions:
- The presented methods enable the biochemical purification of mtDNA nucleoids.
- These techniques will aid in characterizing the protein environment of mitochondrial DNA.
Related Concept Videos
01:24DNA Isolation
01:34DNA Isolation