OneStep polymer HRP is the enzyme polymer conjugated with secondary antibodies. The labeled polymer does not contain avidin or biotin, thus, non-specific staining caused by endogenous biotin is completely eliminated. It utilizes a novel controlled and compact enzyme polymerization technology to achieve higher sensitivity without background. The secondary antibody is intended for use with primary antibodies from rabbit for localization and identification of specific antigens on a slide mounted tissue sections by light microscopy.