Purification of oligo dG-tailed Okayama-Berg linker DNA fragments by oligo dC-cellulose chromatography.

A simple procedure for preparation of oligo dG-tailed DNA fragments is presented. The fragments are first purified by ultracentrifugation through sucrose gradients at low salt concentration. Appropriate gradient fractions are then adjusted to 1 M NaCl and immediately applied to a column of oligo dC-cellulose equilibrated in buffered 1 M NaCl at 4 degrees C. Fragments are eluted with water at room temperature. Passage through the column achieves, in one step, the concentration and purification of oligo dG-tailed DNA fragments free from sucrose.