(A) Genotyping of mice. Total DNA was isolated from tail biopsies, and it was utilized as template in a PCR reaction with following oligonucleotides: Forward, 5’-CATGTTCGATGGGAAAGTCCC-3’; Reverse 1, 5’-CCAGCGCAGCTCAGAGAAGCCA-3’; and Reverse 2: 5’-AGGTGAGATGACAGGAGATC-3’. The F1/R1 oligonucleotides amplified a 112 bp band in WT (PARP1+/+) mice, and F1/R2 oligonucleotides amplified a 350 bp band in PARP1-/- mice. Amplification of both bands indicated PARP1+/- genotype. (B) Confirmation of mitochondrial fractions purity by PCR. Mitochondria Isolation Kit for Tissue (Abcam110168) was employed to isolate mitochondrial fractions. Total DNA from mitochondrial fractions was utilized as template in traditional PCR with gene-specific oligonucleotides to amplify for 28 cycles the 7S mtDNA fragment (184 bp) and GAPDH nuDNA fragment (101 bp). The PCR amplicons were resolved on 1.5% agrose gel. Note the amplification of nuDNA fragment was not noted in mitochondrial fractions.