The maturation of the precursors of mRNA to a functional transcript in eukaryotic cells is a complex, multistep process. It includes the formation of RNP complexes and the splicing procedure. Also, the presence of snRNA packaged as snRNP particles plays an important role in this process. In addition, snRNPs are involved in various autoimmune diseases in which autoantibodies are directed against components of these particles. Relevant techniques which are used to investigate RNA processing, splicing, protein-RNA complex formation and interactions as well as autoantibodies in basic and clinical research are presented in this laboratory manual. The book features easy-to-follow, step-by-step protocols and provides background information and full practical details.