(a)

(b)

(c)

(d)

(e)

Figure 1: Some of the major damaged termini of free radical-mediated DNA strand breaks. (a) 3′-phosphoglycolate (PG). (b) 3′-phosphoglycoaldehyde. (c) 3′-formyl phosphate. (d) 3′-keto-2′-deoxynucleotide. (e) 5′-aldehyde.