crude extracts derived from unirradiated xp groups a , c and g cells were unable to excise dimers from their own nuclear sonicates , native chromatin and whole-cell sonicates prepared after exposure to 100 j/m2 of u.v . radiation at 254 nm , while normal-cell extracts were able to do so from all substrates including purified dna .
C1520168
xp
C0007634
normal-cell