Abstract: Specific cavities which can incorporate nucleosides or nucleotides were prepared in a crosslinked polyacrylamide hydrogel by free radical copolymerization of acrylamide, the nucleobase vinyl monomer, methacrylamide-benzeneboronic acid (MABB) and N,N'-methylenebisacrylamide in the presence of a nucleoside or nucleotide as the imprinting molecule. After washing out the imprinted molecules, their incorporation into the hydrogel was evaluated by measuring the concentration of imprinted molecules in the supernatant solution. The results suggest that when both 9-vinyladenine and MABB were used as the affinity ligands and adenosine or thymidine was imprinted, hydrogels were formed with specific cavities incorporating the imprinted molecules. The application of this system in capillary gel electrophoresis will he discussed