13C spectrum of oligodeoxynucleotide 18 annealed with its complement to yield the duplex 5'-d(GCTAGCXAGTCC)-3'•5'-d(GGACTCGCTAGC)-3', X=γ-13C-OH PdG, adduct 2, collected as a function of temperature. The bottom spectrum was collected at 4 °C, the middle spectrum at 25 °C, and the top spectrum at 37 °C. Assignments of resonances: a, aldehyde 3; b, hydrated-aldehyde 3a; c, carbinolamines 4.