Studies on the nucleotide arrangement in deoxyribonucleic acids VIII. A comparison of procedures for the determination of the frequency of pyrimidine nucleotide runs

Two DNA preparations of mammalian origin, viz., the DNA from calf thymus and the DNA from human spleen, were employed in a comparative study of different methods suitable for the investigation of the arrangement of pyrimidine nucleotides in the polymer chain. The conditions under comparison were (a) the degradation of DNA with dilute sulfuric acid; (b) the degradation of DNA with formic acid-diphenylamine; (c) the degradation of apurinic acid with dilute alkali. The released pyrimidine nucleotide runs of length 1 to 6 were determined directly by two-dimensional paper chromatography.

The range and validity of the several procedures described here and in the literature are considered in detail and the bearing of the findings on the general problem of the nucleotide sequence in DNA is discussed.