The human adaptive immune system relies on the biochemical pathway of antigen proces-sing and presentation to be able to tell which cells are healthy and which are infected,diseased, or cancerous. This pathway starts from the proteolytic processing of proteinantigens and generation of small peptide fragments which are loaded onto nascent MajorHistocompatibility Complex (MHC) molecules and ends with the recognition of thepeptide-MHC complexes by specialized immune receptors on T cells and Natural Killercells. Studying this pathway has tremendous reprecursions on our understanding of humanimmunology and the basic mechanisms that underlie normal immune responses to infec-tions and cancer as well as aberrant responses towards self that lead to autoimmunity. Manyhighly complex assays and techniques have been devised by research groups around theworld to help pick apart molecular events along this pathway. Sharing detailed experimentalprotocols is critical to best coordinate experimental efforts that will carry the field forward,validate key findings, and help newcomers make meaningful contributions. This bookfocuses on exactly that. A series of cutting-edge protocols and methods are presented indetail to allow reproduction and empower future research. The book focuses on the analysisof key molecules and processes along the Antigen Processing and Presentation pathway,starting from how to make and analyze MHC molecules and their cargo (Chapters 1, 2, 3, 4,5, and 6), analyzing the function of chaperones that regulate antigen presentation (Chapters7 and 8) and of enzymes that generate antigenic peptides (Chapters 9, 10, and 11), how tomake and analyze T cell receptors (Chapters 12, 13, and 14), and finally presenting a series offunctional assays to follow adaptive immune responses to antigen presentation (Chapters 15,16, 17, 18, and 19). (MIMB 2026)