Abstract: The present invention relates to biopolymer detection methods based on antigen-antibody interactions, wherein the methods show improved S/N ratios, improved detection sensitivities, and reduced detection times. The present invention also relates to application of these methods to biochips. The invention further relates to antibody fixation methods wherein antibody molecules are immobilized to amide group-containing gels, or amide group-containing gels on insoluble substances. Using such gels prevents the nonspecific adsorption of antibody-binding molecules. By embedding these antibody-binding molecules in such gels, their antibody-binding activity is prevented from deteriorating.