Faraday communications. Electron conduction and trapping in DNA. An electron spin resonance study

Exposure of intercalated DNA to γ-rays at 77 K gives two radical anions, identified as thymine (T˙–) and intercalator (int˙–) radical anions. Growth of the Int˙– signal follows an exponential law with 50% scavenging of T˙– at ca. 1 : 110 (Int˙– to base pairs). Thus on average, electrons traverse ca. 200 bases before becoming trapped.