a thymidine(6-4)thymidine in DNA => a thymidine dimer in DNA
a thymidine(6-4)thymidine in dna => a thymidine dimer in dna
a thymidine(6-4)thymidine in DNA => a thymidine dimer in DNA
a thymidine(6-4)thymidine in dna => a thymidine dimer in dna