Anion-exchange separation of nucleic acids

Solvents for salt-gradient anion-exchange separation of nucleic acids, especially double-stranded DNA and especially by liguid chromatography, are improved by replacing NaCl as the eluting salt with any of a wide range of alkyl ammonium salts and can be used to elute nucleic acids in strict order of increasing length, with reduced sensitivity to elution temperature and salt concentration. Anion-exchange chromatography with these solvents is well suited for identification of DNA fragments on the basis of size, with greater accuracy, precision, and resolvable size range than often is possible with gel electrophoresis.