Three monoclonal antibodies specific to the recombinant preS₂ peptide were prepared using preS₂-β-galactosidase as an immunogen. All three were classified as immunoglobulin M. One of the three monoclonal antibodies (040-01) was precipitated by 6% PEG and used for the preparation of immunoadsorbent column. This immunoaffinity column was utilized to purify recombinant preS₂ peptide which was solubilized and extracted from sonicated E. coli cells. For the storage of this specific antibody, 0.1 M glycine-HCl buffer (pH 2.5) gave the best result. Other buffers tested in this study caused a significant decrease in antibody reactivity. The binding capacity of an immunoadsorbent column for preS₂ peptide was determined using preS₂-ABEI-H conjugate.