Preparation of Polyacrylamide Gels Containing Active Esters

This chapter presents the procedures for preparation of polyacrylamide gels containing active esters. The matrices are formed by copolymerization of bifunctional molecules, containing acryloyl groups and N-succinimidyl esters, with acrylamide and bisacrylamide. The affinity gels thus prepared had the advantages that (1) ligands containing free amino groups readily displaced the active ester resulting in the formation of stable amide bonds between the ligands and the polyacrylamide gel, (2) the displacement reaction was readily followed by measuring cleavage of the esters, (3) the matrix was resistant to chemical and microbial degradation, (4) ligand levels were easily controlled, and high ligand concentrations were obtained, (5) porosity and shape of the gel matrix were easily controlled, and (6) the matrix was hydrophilic, but low in extraneous ionic charge. Carbohydrate ligands in the form of glycosides containing an amino group in the aglycon were immobilized by the reaction of the amino group and the active esters in the gel and used to demonstrate specific adhesion of intact cells to carbohydrates.