For this purpose, mitochondria were isolated using a discontinuous Percoll gradient centrifugation followed by RNase I treatment to the isolated DNA to remove any traces of RNA contamination. 
Percoll
For this purpose, mitochondria were isolated using a discontinuous Percoll gradient centrifugation followed by RNase I treatment to the isolated DNA to remove any traces of RNA contamination. 
RNase I
The mitochondrial DNA was isolated from mitochondrial samples by commonly used CTAB method. 
CTAB