Frank Jung, Constantin E. Sekeris, and Johannes Schenkel: Isolation and Immunochemical Characterization of hnRNP Particles.-Ruth Sperling and Joseph Sperling: The lnRNP Particle -- A Naturally Assembled Complex of Pre-mRNA and Splicing Factors.-Karl Otto Greulich: Intrinsic Fluorescence Techniques for Studies on Protein-Protein and Protein-RNA Interactions in RNP Particles.-Ulf Skoglund, Lars-G?ran ?fverstedt, and Bertil Daneholt: Procedures for Three-Dimensional Reconstruction from Thin Sections with Electron Tomography.-Berthold Kastner: Purification and Electron Microscopy of Spliceosomal snRNPs.-Panayiotis G. Vlachoyiannopoulos: Detection of Autoantibodies to Extractable Cellular Antigens.-Martin Bl?thner: Methods in Immunolocalization of Autoantigens.- Johannes Schenkel, Frank Jung, Apostolia Guialis, and Angela Kr?mer: In Vitro Splicing of Pre-mRNA in HeLa Extracts.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 to investigate RNA processing, splicing, protein-RNA complex formation and protein-RNA interactions as well as the use of autoantibodies in basic and clinical research are presented in this manual.A practical tool for anyone working at the lab bench Easy to follow step-by-step protocols Background information and full practical details Information stored in DNA needs to be translated into functional proteins. Ribonucleoprotein (RNP) particles play a major role in this process. In many autoimmune diseases, antibodies are directed against components of these particles. Detailed protocols for analysing the structure and functl#Ï