en Immunology Immunology پژوهشي Research <div> <p><strong>Introduction: </strong>The major histocompatibility complex (MHC) is a group of cell surface proteins that are essential for recognizing foreign molecules in human and other mammals. The physiologic function of MHC molecules is the presentation of peptides to T cells. In this study, we evaluated the purification of a class II MHC molecule (HLA-DR) from a human Burkitt&prime;s lymphoma cell line; Daudi.</p> <p><strong>Materials and methods:</strong> We described a simple procedure for purifying human HLA molecules from the cells lysate. As a representative model, HLA-DR was purified from Daudi cell line. The cell membrane was solubilized by a buffer contained NP-40 detergent. Subsequently, the isolation of the membrane antigen was carried out by affinity chromatography method using mouse anti-human HLA-DR monoclonal antibody. The size and the specificity of the purified antigen were determined by Bradford and ELISA methods, respectively.</p> <p><strong>Results:</strong> The purified HLA antigen was obtained in approximately 20-30 micrograms in each run of chromatography. Additionally, ELISA method demonstrated the HLA-DR specificity of the purified protein. &nbsp;</p> </div> <p><strong>Conclusion:</strong> The results indicated that affinity purification of HLA-DR antigen by means of specific monoclonal antibody is a simple and fast procedure for obtaining the purified antigen.</p> HLA-DR, Affinity chromatography, ELISA 34 38 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-212-3&slc_lang=en&sid=1 Zahra Khayyati za.khayyati@gmail.com 10031947532846002583 10031947532846002583 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran Fatemeh Yari f.yari@ibto.ir 10031947532846002584 10031947532846002584 Yes Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran