the four dna samples designated t-dna , b-dna , t ( f ) -dna , and b ( f ) -dna respectively were hydrolyzed with formic acid-diphenylamine , and the pyrimidine oligonucleotides of various chain lengths ( isotichs ) were ractionated by deae-celluclose chromatography .
C0012854
dna
C0919262
b