[Preparative isolation of mono- and di-pyrimidine nucleotides from depurinated herring sperm DNA (author's transl)]

The preparative isolation of DNA fragments with defined sequences from hydrolysates of naturally occuring DNA is proposed as an alternative to their complicated synthesis and has been partially realised. Starting with herring sperm DNA which was depurinated in 100 g batches, one obtains 35-40 g of a pyrimidine-oligonucleotide mixture which is separated into high and low molecular weight fragments via column chromatography on DEAE cellulose. The low molecular weight pyrimidine-nucleotide mixture thus obtained is then selectively separated on a preparative scale into fragments with one and two monomer units by means of a three-step separation procedure on QAE-Sephadex.