QUANTITATIVE-ANALYSIS OF MITOCHONDRIAL-DNA DELETION IN PARAFFIN-EMBEDDED MUSCLE TISSUES FROM PATIENTS WITH KSS AND CPEO

The percentage of common deletion of mitochondrial DNA (mtDNA) was det ermined quantitatively by a PCR-based, non-radioactive method in DNA e xtracted from formalin-fixed, paraffin-embedded skeletal muscle tissue s from two patients with Kearns Sayre syndrome (KSS) and one with chro nic progressive external ophthalmoplegia (CPEO). The method involved P CR cycle titration of wild-type and deleted mtDNA in parallel, stainin g of gel bands with the sensitive fluorescence dye SYBR Green I, and q uantitation of intensity on a computer screen by the NIH image program . We determined 75% and 71% common deletion of mtDNA in the KSS patien ts and 35% in the CPEO patient.