An antimicrobial article, a cell culture article, an antithrombotic article, or a biopharmaceutical article that can reduce adhesion of proteins, blood components, cells, or bacteria containing a copolymer that contains a polymerized unit (A) represented by —;CH2—;CHOH—; and a polymerized unit (B) represented by —;CH2—;CX2—;, wherein Xs are the same as or different from each other, and are each an alkyl group having a linear, branched, or cyclic structure, and optionally containing an oxygen atom between carbon atoms, an alkoxy group having a linear, branched, or cyclic structure, and optionally containing a hetero atom between carbon atoms, a siloxy group having a carbon number of 3 or greater, an ester group containing an aromatic ring or an alkyl group and having a linear, branched, or cyclic structure, or H, excluding those in which both Xs are H.