1. A method for analyzing an analyte sample, comprising:bringing an analyte sample containing a prostate-specific antigen (PSA) into contact with a carrier having an anti-free PSA antibody immobilized thereon, thereby binding free PSA to the anti-free PSA antibody immobilized on the carrier;
thereafter bringing the carrier in which the free PSA is bound to the immobilized anti-free PSA antibody into contact with a monoclonal antibody capable of specifically recognizing galactose having a terminal sialic acid residue through an ?(2,3) bond in an N-type glycan, thereby binding the monoclonal antibody to the free PSA bound to the anti-free PSA antibody immobilized on the carrier; and
measuring the amount of the monoclonal antibody bound to free PSA, thereby measuring the amount of free PSA having an N-type glycan in which a terminal sialic acid residue is bound to galactose through an ?(2,3) bond.