Figure 2. Detection of mitochondrial deoxyribonucleic acid heteroplasmy using SURVEYOR mismatch endonuclease on 4% polyacrylamide gel. Abbreviations: Lanes A, D, F, H, J, undigested PCR products; lanes B, E, G, I, K, digested PCR products with SURVEYOR mismatch endonuclease (Transgenomic); lane C, size marker (100 bp Ladder plus, Thermo Scientific). Lane A, a negative control for heteroplasmy (homoplasmic sample); lane B, a positive control for heteroplasmy (heteroplasmic sample). Stars indicate the location of cleavage fragments. Lanes D, E: LHON-1, 15 amplified fragment; lanes F, G: LHON-2, 15 amplified fragment; lanes H, I: LHON-3, 4 amplified fragment; lanes J, K: LHON-4, 14 amplified fragment.