we obtained 34 subclones; the one with the most prevalent T15091C mtDNA possessed 34% T15091C mtDNA. After four more rounds of subcloning, we isolated five P29 subclones with more than 95% T15091C mtDNA, and one of them was used as P29-95. (C) Identification and quantification of T15091C mtDNA with an additional G9976A mutation in the ND4L gene in subclone P29-95 by BstNI digestion of the PCR products.