The solubilized form of human CD2 (sCD2), which consists of D1 and D2 domains and can bind specifically to LFA-3, was produced by secretion from Pichia pastoris by use of the AOX1 promoter and the alpha-factor signal sequence. An anti-peptide antibody against the C-terminal region of sCD2 (anti-PC-CD2-12 antibody) was used for ELISA, purification and characterization of sCD2. Secreted sCD2 was purified from fermentation broth with an affinity column coupled with anti-PC-CD2-12 antibody. The concentrations of sCD2 in fermentation broth and purified fractions were measured with the anti-peptide antibody and a monoclonal antibody recognizing the D1 domain. These results suggest that a large portion of secreted sCD2 lacked several amino acids in the C-terminal region probably because of digestion by proteases. Therefore, purification by the anti-peptide antibody recognizing the C-terminal region is a promising method for the purification of sCD2 having the complete C-terminal region.