Antigen presentation is the process where a foreign body or a microbial antigen is presented to the T lymphocytes of the acquired immune system and eliminated from the body. For studying the mechanism of this process, antigen presentation assays can be applied. Three main stages of the mechanism should be studied: antigen uptake, antigen processing and antigen presentation. For these assays, the antigen, T lymphocytes, and antigen presenting cells are essential to carry out the assays. T cell hybridoma could be generated in the lab to be used instead of the primary T cells. This article focussed on a technical issue in immunology: the procedures and advantages. In this work, antigen presentation assays were highlighted by using two peptides from M5 protein of Streptococcus pyogenes as the antigen, T cell hybridomas specific for these peptides as T lymphocytes and macrophages as the antigen presenting cells. The results reflected the application of these assays and their advantages as a fundamental technique in immunology. That facilitates the study of immune responses against microbial antigens and designing vaccines against them................. Keywords: ................Antigen presentation assays; T cell hybridoma; Antigen uptake; Antigen processing, Antigen presentation.