Separation of alkylated guanines, adenines, uracils and cytosines by thin-layer chromatography

A one-dimensional thin-layer chromatographic (TLC) method using a mixture of two solvents and commercially available silica gel plates to separate mixtures of alkylated guanines, adenines, uracils and cytosines is presented. RF values for the bases and the solvent systems used are listed. The addition of approximately 1 ml of ammonium hydroxide to the solvent has been found to prevent streaking and results in non-distorted developed spots. A mixture of 19 adenine and uracil bases was resolved on silica gel plates employing two-dimensional TLC. Chloroform-methanol (90:10) was used for the first dimension and chloroform-propanol (90:30) for the second.