Influence of protein identity on DPC yield for reductive amination. Denaturing PAGE analysis of DPCs visualized via protein staining using SimplyBlue stain. Lane 1 and 10: protein size markers; Lanes 2–9: DPC formation between aldehyde-containing DNA and AlkB, histone H4, ribonuclease A, and myoglobin. Lanes 2, 4, 6, and 8 correspond to reactions conducted in the absence of DNA and NaCNBH3 (negative controls). The cross-linking reactions were conducted using the 2:1 protein:DNA molar ratio.